battleye has supported proton for a decent amount of time now, its easy to enable for proton, valve will take care of your game with proton aswell, i dont see a reason why you wouldn't allow linux/steamdeck players to play your game, and no, cheaters isnt a excuse, you can easily ban these players and there are plenty of other games that do support proton and dont have huge amounts of cheaters because they ban them. linux desktop and steamdeck are growing at a fast rate with it going from around 1% to 4% desktop market in just under 2 years, beating mac os by the way in the gaming market share on steam. so again i dont understand why you are not allowing linux players, all the bug reports will be going to valve to handle your game on linux so its not like you have to rlly invest in any money to actually support it, like you would if you were bringing native support for the game on linux. and yes i know bungie has other anticheat solutions, so does lots of other games that support proton. that would be only the time you would need to invest into getting proton supported with your game so please enable it bungie, lots of linux players would gladly play your game on both handheld and desktop