This mod is awesome. I'm working with RGC right now and we noticed that on server games the trains derail for no apparent reason. I'm trying something with increased wheel lips on the front and rear of the locomotive to see if that helps. Also, for placing tracks I've been using the move placeables mod and it was a game changer for lining up pieces.
If you'd like my version of BNSF_SD40 with the extra wheel parts let me know and I'll gladly send it to you.