Haven't bothered to read the whole thread, but I seem to recall that the Nissan S-bodies (s13-s15) has got about 41-42 degrees lock in stock form. With a simple spacer it can easily be increased by at least 5-6 degrees...
And as for realism being the main argument for not allowing more lock, I must say that I don't know many stock cars that will let you adjust gear ratios, damper settings, diff settings, alignment etc. like you can with the XRT. IRL it would be way easier to increase steering angle than adjust ackerman...!
And yes, you do need more lock to drift properly. Of course one can drift with 36 degrees, but when chasing those insane entry angles it just won't do the job.
Grip racers will never get this though, as they're afraid of pushing the limits beyond what's "safe"
(Btw, I have 15 years of IRL racing experience, yet I love drifting! It's all about pushing limits and having fun in a car isn't it?)