I did have some issues, but the big one is fixed with the flicker cog. What a great script!
Lighting is a bit funny with terrain 3dos, especially with flicker as it will change shades when you enter darker sectors. My lighting sucks anyway, so I guess I shouldn't worry about something little like this.
Is it possible to have different sounds on different parts of the 3do? In level 11 I made some rock hills and just for appearances sake I added different mats. The hill was mostly a rock mat but I had some grass ones that I tried to put a dirt sound on, but it didn't work so I removed them.
I guess the only real difficulty is cutting them up with ZED. When you start working on funny angles it's hard to see when you're cutting away parts that you don't want to and there are a hundred little vector lines.
Anyway I did make a 3do for the first little part of level 13 and it's staying, warts and all.