> If the change is that Firefox now allows the system-level picker to get through instead of blocking the keyboard shortcut, that’s a win.

You're almost there :) Firefox now opens the system-level picker for that shortcut, regardless of what global keyboard shortcut you might have configured system-level. So system-level, I have nothing done on "CTRL + .", in Firefox, I have 1Password browser extension triggered by "CTRL + ." so when Firefox version 150 was launched, instead of seeing 1Password when I did the shortcut, it instead showed my system-level emoji picker (which I have no shortcut for), triggered by Firefox.

Okay, now I’m back to being annoyed. :)

Why can’t Firefox respect system-level custom keyboard shortcuts? This has been a bug on Mac for like 15 years and they don’t seem to care about it at all, which IMO is ridiculous, it’s core system functionality.