I have a custom tool and I like to use the Cnr-T shortcut for it (tool is an improved select-none).
For some reason, every time I open SketchUp, this shortcut is reset to the default (select-none).
All other shortcuts are persistent, just not this one.
I don’t see any updates in the SharedPreferences.json file after setting this shortcuts neither.
I think the problem is that Ctrl + T is wired to “Edit/Select None” by the Edit menu itself. On Windows you can temporarily reassign a menu-defined shortcut keychord, but it won’t stick the next time SketchUp is launched because the menu setting gets first shot. Depending on what you think should happen, either the user setting should stick or they should be prevented from re-using that keychord in the first place. Either way, I regard the existing behavior as a bug.
The Mac also has Edit/Select None wired in the menu to cmd-shift-A, but unlike Windows it does not allow any user shortcuts to use the cmd key so a per-session reassignment isn’t possible.