a way/option/button to LOCK MIDI IN PLACE EDITOR track size, so that it is independent from other tracks resizing

I’d like to resize tracks so that I can see more tracks on screen, but without shrinking the midi in-place editor I’m currently working in.

I am not sure what exactly you want to do. So if you would exaclty in detail would explain your workflow maybe there is a quick way of helping you.

Try this:
Look up the feature “Divide Track List”.
Move your InPlace Midi track up to the upper track list.
Now you can execute resize track commands in the lower list while the size of the upper track gets preserved.