@felmue
without removing the small pcb it would not be possible to stack any module, sure!
But, the problem is not the fitting of the COMMU to the M5Core2, but to complete the stack with the base plate (the one with the battery that was removed from the M5Core2 before!). This base plate just does not fit to the COMMU. Why? There does not seem to be any good reason why it was designed like this !?!
And, no, I have no other module that fits to the M5Core2. And I will not buy another one until I know that it will fit!

When buying the M5Core2 (instead of the M5Stack), I thought that it would be an improved version of the M5Stack with advanced features. But I did not see any hint that it is not mechanically compatible. This is really bad for a modular solution like the 'M5Stack'.

BR, Jörg.

PS: it seems that the M5Go Battery Bottom 2 could be a solution

@felmue
without removing the small pcb it would not be possible to stack any module, sure!
But, the problem is not the fitting of the COMMU to the M5Core2, but to complete the stack with the base plate (the one with the battery that was removed from the M5Core2 before!). This base plate just does not fit to the COMMU. Why? There does not seem to be any good reason why it was designed like this !?!
And, no, I have no other module that fits to the M5Core2. And I will not buy another one until I know that it will fit!

When buying the M5Core2 (instead of the M5Stack), I thought that it would be an improved version of the M5Stack with advanced features. But I did not see any hint that it is not mechanically compatible. This is really bad for a modular solution like the 'M5Stack'.

BR, Jörg.

PS: it seems that the M5Go Battery Bottom 2 could be a solution

Trying to use the COMMU with the Core2, I find that it does not fit correctly (the base interferes mechanically at some points). That is a little strange.
You promised to work on the documentation nine months ago. Is there a compatibility list in the meantime?
How can I find out which modules fit to Core2? Without this, the Core2 is nearly useless for me.