I'm not fast by any means, but I don't understand what's the trouble of RAC. Doesn't seem that poisoness to me infact, I have more trouble with the mrt, bf1 without TC, etc. Just go smooth, brake early, get on the power early and keep it balanced. The turbo makes it more complicated as you need to get on the power earlier and so it will step out frequently, but so do the LX6, FZ5, F08 etc. so I'm not sure what makes the RAC any different there.
I get the impression that those who have trouble tend to go in too hot/fast so they have to lift, causing the huge RAC understeer. Don't drive so agressively, but plan your corners in advance, in slow, out fast.
Anyway, on the road (and likely on a track in RL) you'd likely drive much more carefully then you would in LFS, and driving the RAC in similair fashion in LFS even with the default setup is as hard as driving my sister's Daihatsu.