Evening Mike,
I didn't realise there was also the same problem in 4mm, mind you saying that I was also into EM back in the late 80's so being that I use to make my own track back then I wasn't aware of the problem.
The wheel drop definitely seems to affect the longer wheelbase stock, I did make a video years ago showing the problem, I will see if I can find it and put it up on here, the wheel drop is not that bad in my opinion.
Martyn.