Hello
thanks for your comment!
I made a new version to fix the problem with the pedals values (it was an error in how the values are stored and calculated) . Now you can press throttle and clutch pedals and get 100, but depending on the hardness of the pedals of your steering wheel you may not get the maximum value (100). For example I never get 100 with the brake pedal in my Logitech G29 but I get easy 100 in clutch and throttle pedals.
On the other hand, about your problem with project cars 2. I don't have this game, but I think the force feedback with proton does not work in project cars 2 as there is an issue about force feedback for this game in the proton github. I have project cars 1 and force feedback works properly but keep in mind that PyLinuxWheel is not a driver for Logitech wheels. PyLinuxWheel is only a program to configures the values of the Logitech kernel driver. So the support of your steering wheel in a game with proton depends on proton and the kernel driver.