diff --git a/.github/workflows/examples-efr32.yaml b/.github/workflows/examples-efr32.yaml
index 76d5e322f579ff..b54a80ee3f3935 100644
--- a/.github/workflows/examples-efr32.yaml
+++ b/.github/workflows/examples-efr32.yaml
@@ -32,7 +32,7 @@ jobs:
             BUILD_TYPE: gn_efr32
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -46,6 +46,17 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              shell: bash
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -82,6 +93,7 @@ jobs:
                   scripts/examples/gn_efr32_example.sh examples/window-app/efr32/ out/window_app_debug BRD4161A
                   .environment/pigweed-venv/bin/python3 scripts/tools/memory/gh_sizes.py efr32 BRD4161A window-app \
                     out/window_app_debug/BRD4161A/chip-efr32-window-example.out /tmp/bloat_reports/
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-esp32.yaml b/.github/workflows/examples-esp32.yaml
index fd40daa2480a73..858a7f6aedd22a 100644
--- a/.github/workflows/examples-esp32.yaml
+++ b/.github/workflows/examples-esp32.yaml
@@ -32,7 +32,7 @@ jobs:
             BUILD_TYPE: esp32
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -47,6 +47,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -103,6 +113,7 @@ jobs:
             - name: Build example IPv6 Only App
               timeout-minutes: 10
               run: scripts/examples/esp_example.sh ipv6only-app sdkconfig.defaults
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-infineon.yaml b/.github/workflows/examples-infineon.yaml
index 0f441038a8ddd1..05174f70243398 100644
--- a/.github/workflows/examples-infineon.yaml
+++ b/.github/workflows/examples-infineon.yaml
@@ -31,7 +31,7 @@ jobs:
         env:
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -44,6 +44,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -71,6 +81,7 @@ jobs:
                 .environment/pigweed-venv/bin/python3 scripts/tools/memory/gh_sizes.py \
                     p6 default all-clusters-app \
                     out/infineon-p6-all-clusters/chip-p6-clusters-example.out
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-k32w.yaml b/.github/workflows/examples-k32w.yaml
index 1c0a563f0ad45c..76e0f5f7873545 100644
--- a/.github/workflows/examples-k32w.yaml
+++ b/.github/workflows/examples-k32w.yaml
@@ -31,7 +31,7 @@ jobs:
             BUILD_TYPE: gn_k32w
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -45,6 +45,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -83,6 +93,7 @@ jobs:
                     k32w k32w061+se05x+release lighting-app \
                     out/lighting_app_se_release/chip-k32w061-light-example \
                     /tmp/bloat_reports/
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-linux-standalone.yaml b/.github/workflows/examples-linux-standalone.yaml
index 8d9e07118a74da..0c0735f97dea4d 100644
--- a/.github/workflows/examples-linux-standalone.yaml
+++ b/.github/workflows/examples-linux-standalone.yaml
@@ -31,7 +31,7 @@ jobs:
             BUILD_TYPE: gn_linux
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -46,6 +46,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 10
               run: scripts/build/gn_bootstrap.sh
@@ -123,6 +133,7 @@ jobs:
                     linux debug ota-requestor-app \
                     out/ota_requestor_debug/chip-ota-requestor-app \
                     /tmp/bloat_reports/
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-mbed.yaml b/.github/workflows/examples-mbed.yaml
index 006ea73c483163..23bc0573e8563c 100644
--- a/.github/workflows/examples-mbed.yaml
+++ b/.github/workflows/examples-mbed.yaml
@@ -34,7 +34,7 @@ jobs:
             APP_TARGET: CY8CPROTO_062_4343W
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -50,6 +50,15 @@ jobs:
               with:
                   submodules: true
 
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 10
               run: scripts/build/gn_bootstrap.sh
diff --git a/.github/workflows/examples-nrfconnect.yaml b/.github/workflows/examples-nrfconnect.yaml
index 7df872e55437d7..8f3f8bc026a4db 100644
--- a/.github/workflows/examples-nrfconnect.yaml
+++ b/.github/workflows/examples-nrfconnect.yaml
@@ -31,7 +31,7 @@ jobs:
             BUILD_TYPE: nrfconnect
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -46,6 +46,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -144,6 +154,7 @@ jobs:
               timeout-minutes: 10
               run: |
                   scripts/run_in_build_env.sh "scripts/tests/nrfconnect_native_posix_tests.sh native_posix_64"
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-qpg.yaml b/.github/workflows/examples-qpg.yaml
index 7eb35b94123ee2..ee90789371c815 100644
--- a/.github/workflows/examples-qpg.yaml
+++ b/.github/workflows/examples-qpg.yaml
@@ -31,7 +31,7 @@ jobs:
             BUILD_TYPE: gn_qpg
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -45,6 +45,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Bootstrap
               timeout-minutes: 25
               run: scripts/build/gn_bootstrap.sh
@@ -85,6 +95,7 @@ jobs:
               timeout-minutes: 5
               run: |
                   config/qpg/chip-gn/build.sh
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}
diff --git a/.github/workflows/examples-telink.yaml b/.github/workflows/examples-telink.yaml
index d30a655f97eb45..45557aa3f393d4 100644
--- a/.github/workflows/examples-telink.yaml
+++ b/.github/workflows/examples-telink.yaml
@@ -29,7 +29,7 @@ jobs:
             BUILD_TYPE: telink
             GH_EVENT_PR: ${{ github.event_name == 'pull_request' && github.event.number || 0 }}
             GH_EVENT_HASH: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
-            GH_EVENT_PARENT: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
+            GH_EVENT_BASE: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event.before }}
 
         runs-on: ubuntu-latest
         if: github.actor != 'restyled-io[bot]'
@@ -44,6 +44,16 @@ jobs:
               uses: actions/checkout@v2
               with:
                   submodules: true
+
+            - name: Get parent for size reports
+              run: |
+                MERGE_PARENT="$(git --no-pager log -1 --pretty=tformat:%s | sed -n -e 's/Merge [0-9a-f]\+ into //p')"
+                if test -z "${MERGE_PARENT}" || test "${GH_EVENT_PARENT}" = 0
+                then
+                  MERGE_PARENT=$GH_EVENT_BASE
+                fi
+                echo "GH_EVENT_PARENT=$MERGE_PARENT" >>$GITHUB_ENV
+
             - name: Build example Telink Lighting App
               run: |
                 ./scripts/run_in_build_env.sh \
@@ -52,6 +62,7 @@ jobs:
                   telink tlsr9518adk80d lighting-app \
                   out/telink-tlsr9518adk80d-light/zephyr/zephyr.elf \
                   /tmp/bloat_reports/
+
             - name: Uploading Size Reports
               uses: actions/upload-artifact@v2
               if: ${{ !env.ACT }}