First off, this mod is absolutely incredible! I don't know how much the physics were tweaks for the modded cars but coming from Assetto Corsa, some of these cars are spot-on in hardcore mode!
I have one request though: make Hardcode mode unlocked by default, or at least make it an option to gain champion status by default.
It took me several hours to unlock and I basically cheesed it by buying cars and doing a single challenge over and over again. I have several friends who won't try this game coming from Assetto Corsa simply because of this limitation. Sim racing enthusiasts like me would be crawling all over this game if hardcore mode could be used from the get go.