It might be useful as an option for some people, but holding down the botton would slow you down by at least making you change finger positions and at worst limit your commands. For the meantime I'd recommend trying a button like Alt as your 1 key so you don't have to move much. Ideally you need to be able to use your movement, throttle, voice, stamina, and number keys simultaneously and you can't do that with the number keys anyways. My favorite gaming peripheral is a mouse with two side buttons, and my 1234 keys are Space Mouse3 Mouse4 Q
Shwalbe I couldn't recreate a key limit by pressing 2 directions, crew voice, jump, map, and tab