Depends on the primary motivation of the request (to be clarified).
If he doesn't want to use keyboard, this would not work.
Otherwise it's a very viable alternative.
I dont know all the hotkey´s, i know Q and E (but you need also the select the fire mod!) but i like to use the arrows to move map witch is all the other way in keyboard.. but the point is to apease new players, mobile players and like me lazy players. it´s a big plus in mobile not having to double tap fire mode. I see people are streaming in twitch and new players and casual just want to have fun, they dont know the hotkeys, also make the game faster for audience watching.
About the "weapon board", i dont get all the resistence since its just a reskin of the current system of the "msdos box" for an image (intead of openning the boxes opens an image with the same info), also as milsim player, its kind of the same system to make a gun switch firemodes IRL witch i love (dopamine kick when you do the firemods clicks in a round starts in a paintball)
Ps: i know this is also for my personal enjoyment of the game just giving the advocacy speech