A modified computer is already being checked for in CA emissions. No matter how good the car runs, if you have a non-approved or factory tune you can’t register the vehicle.

Homebrew isnt the issue, since it’s not like the stuff coming from Tesla or any actual car maker has to go through a third party approval process. They just throw software updates out to the wild. And while they may have some internal testing, there just isn’t the regulations to verify any of that.

I’ve found the whole concept of software assists in general to be the wild West in automotives.