Currently, the macOS shell seems to receive the key-up event for command sequences like "⌘-C" and "Shift-A" without producing a key up event in the framework for the letters, which is problematic on the framework side when someone wants to type, much less re-map it to something else, and it causes the framework to think that the non-modifier keys never went up, so they stick until someone presses the key again (e.g. if I press "⌘-C", the framework thinks that the "C" key is pressed until it gets pressed again).