How to change command visibility depending on code constraints?

[Agrael1]

I'm working on extension, that has a context menu button, which must be only active in header files and if its filename is present in the map.
I tried UIContexts from the video, but it works only once triggered, then it proceeds to be active everywhere else.
Also I tried BeforeQueryStatus, combining with default invisible, but it does not show, even when Command.Visible is set to true. In fact Command.Visible does not work at all.

How can this be achieved?

Link to repo: https://github.com/Agrael1/IncludeMinimizer