I'm not sure if this is the default UI's fault or what. It seems that when you put Minimal Text as your preferred level of hotkey brevity it doesn't really like that for NUMPAD hotkeys:
I would expect it to shorten it to something like NP1 / NP2 like shift+4 gets shortened to S2 and ALT+1 gets shortened to A1. I searched everywhere in the ui for various things that could be controlling that and i'm honestly not sure if it's UI or a bug that has to go to Daybreak to fix.