After playing for almost 2 hours with controls where i have set keyboard buttons to Steam Deck's buttons, i think the game in general needs a better support for controllers but also better for keyboard as well. i noticed some of the inputs that you can set on controller, you can't set on keyboard. But i also think that for controller, controls for the turret/helicopter should be different than it using Throttle and Brake for going back/down and forward/up cos on controller i like using triggers to go back and forward like in other racing/car game. it's awkward for me to control helicopter when using triggers to go back and forward (can't even imagine how turret would control). Luckily Steam Deck has Action Sets that i can switch between so it's not a big deal. The game is actually very much playable with the bindings i have for it, i just wish for keyboard you could set stuff like Rear view and Camera.
Edit: Editing the Settings.ini fixed the problem above. Had to look up what the input numbers are and i did it on Steam Deck and it works better now.