In the end, the problem isn't really about how the FFB feels, but the physics.
Every car understeers and oversteers at the same time, basically as soon as you start turning in, the car understeers, then it is also very easy to oversteer on the corner exit. It's almost like driving rally cars on dirt. At first, I thought it was because I was driving road cars in the intro events, but after that, I tried the Audi R8 GT3, probably from the premium pack, it was the same story. I've never driven a real GT3 car, but based on experiences in ACC and iRacing, that's probably not how a GT3 car should feel like. Obviously Forza Motorsport is not supposed to compete with ACC and iRacing in terms of simulation, but even discard the details, the basic car dynamics in Forza just doesn't feel right…