diff --git a/.buildkite/ci.mjs b/.buildkite/ci.mjs
index df9e7d2f5b5425..a089cd2020f67c 100644
--- a/.buildkite/ci.mjs
+++ b/.buildkite/ci.mjs
@@ -212,9 +212,10 @@ function getPipeline(options) {
   /**
    * @param {"v1" | "v2"} version
    * @param {Platform} platform
+   * @param {string} [instanceType]
    * @returns {Agent}
    */
-  const getEmphemeralAgent = (version, platform) => {
+  const getEmphemeralAgent = (version, platform, instanceType) => {
     const { os, arch, abi, distro, release } = platform;
     if (version === "v1") {
       return {
@@ -238,6 +239,7 @@ function getPipeline(options) {
       distro,
       release,
       "image-name": image,
+      "instance-type": instanceType,
     };
   };
 
@@ -248,7 +250,8 @@ function getPipeline(options) {
   const getBuildAgent = target => {
     const { os, arch, abi } = target;
     if (abi === "musl") {
-      return getEmphemeralAgent("v2", target);
+      const instanceType = arch === "aarch64" ? "c8g.8xlarge" : "c7i.8xlarge";
+      return getEmphemeralAgent("v2", target, instanceType);
     }
     return {
       queue: `build-${os}`,
@@ -263,9 +266,10 @@ function getPipeline(options) {
    * @returns {Agent}
    */
   const getZigAgent = target => {
-    const { abi } = target;
+    const { abi, arch } = target;
     if (abi === "musl") {
-      return getEmphemeralAgent("v2", target);
+      const instanceType = arch === "aarch64" ? "c8g.large" : "c7i.large";
+      return getEmphemeralAgent("v2", target, instanceType);
     }
     return {
       queue: "build-zig",
@@ -279,7 +283,8 @@ function getPipeline(options) {
   const getTestAgent = platform => {
     const { os, arch, release, abi } = platform;
     if (abi === "musl") {
-      return getEmphemeralAgent("v2", platform);
+      const instanceType = arch === "aarch64" ? "t4g.large" : "t3.large";
+      return getEmphemeralAgent("v2", platform, instanceType);
     }
     if (os === "darwin") {
       return {
diff --git a/scripts/agent.mjs b/scripts/agent.mjs
index bf163de4c578eb..1e8a0e0c74dfe1 100755
--- a/scripts/agent.mjs
+++ b/scripts/agent.mjs
@@ -151,21 +151,29 @@ export async function doAgent(action) {
       "token": token || "xxx",
       "shell": shell,
       "job-log-path": logsPath,
-      "git-mirrors-path": join(cachePath, "git"),
       "build-path": join(homePath, "builds"),
       "hooks-path": join(homePath, "hooks"),
       "plugins-path": join(homePath, "plugins"),
       "experiment": "normalised-upload-paths,resolve-commit-after-checkout,agent-api",
     };
 
+    let ephemeral;
     if (cloud) {
       const jobId = await getCloudMetadataTag("buildkite:job-uuid");
       if (jobId) {
         options["acquire-job"] = jobId;
         flags.push("disconnect-after-job");
+        ephemeral = true;
       }
     }
 
+    if (ephemeral) {
+      options["git-clone-flags"] = "-v --depth=1";
+      options["git-fetch-flags"] = "-v --prune --depth=1";
+    } else {
+      options["git-mirrors-path"] = join(cachePath, "git");
+    }
+
     const tags = {
       "os": getOs(),
       "arch": getArch(),