I am finalizing a track based on 256x256 textures.
In order to avoid in-game lag caused by run-time loading of 256 textures, I made a texture loader, i.e. an object placed near the start and using all textures.
This worked fine, but not perfectly. At some places in the track, the game was loading additional 256 textures. I almost went crazy, because when running with 8 trucks, this caused the number of loaded 256 textures to exceed the magic 63. [When the 64th is loaded, the MTM2 engine discards them all and reloads only the currently visible, thus causing the game to halt for nearly 2 seconds]
After many game restarts and navigation in Gold mode, I was able to identify the models that were causing texture loadings.
They were all using textures already used by other models (especially the texture-loader). So why were these textures loaded again?
Changing the texture mapping of these bins resolved the problem.
Examining the faulty bins with a hex-editor, I noticed that texture names were spelled in lowercase, as opposed to upper case in all other bins.
Conclusions
The MTM2 engine is case sensitive when checking the need to load a texture.
There might be a problem with BinEdit, although I don't know which version produced the faulty bins.