It’s currently possible to assign multiple commands to the same hotkey.
I think the user should be warned before being able to assign a hotkey to more than a single function (i.e. “Already Exists for: X”). Otherwise it is on the user to be aware of all existing hotkeys before creating a new one.
While testing a few I was never able to get a single hotkey to perform multiple functions. It seemed to always pick one of them to perform. I’m not sure how it decided which to perform.
This leads to another potential issue; the assignment of a hotkey to conflicting commands (e.g. focus on pane to the left & focus on pane to the right).