Well, to keep things realistic as LFS supposedly should, it's best to let the steering lock be dictated by whatever RL car the LFS car is based on. For instance, the XR GTT's maximum lock should be determined via the original specifications of the Mitsubishi Starion and so on.
However, IRL, the real limitation on steering lock is the design of the steering system and the clearance the fenders have. In that regard, RL cars tend to be set to maximum safe possible lock in OEM trim, usually with a finite amount of extra lock left for redundancy/safety and ensure a margin of clearance. No point making a car a pig to park and manouver when more lock wn't cause clearance issues ove the suspensions range of travel.
However, as some of us already know to well, it's quite possible to safely get some extra lock out of the system if the fender clearance is still there. I'm not a drifter myself, but I simply can't see what harm 45 degrees of lock would do ATM. If LFS actually physically models the fenders and inadequate fender clearance causes tire rub, then we'll use the maximum safe possible lock as the maximum possible lock setting. As far as I'm concerned, the steering ratio is even more vital if a car has decent lock in the first place, but that setting isn't quite available yet in LFS, even for the race cars.
The ultimate solution to all this is to simply set maximum lock to whatever RL car is based on whilst adding real cars with drifter friendly steering lock such as the fabled S13s. This keeps every reasonable LFS racer/drifter happy.
Well, drifting is a real motorsport these days, so to neglect it now is just silly. As for the hardcore no drift circuit racers, don't worry, figure skating and speed skating have co-existed for a long time and so far both sports are doing well in their own ways.