I've just started making low poly shadow casters so my higher poly objects don't have to cast more costly shadows. So i set this new lower poly object as a shadow caster in Xpacker. I know the idea is that the caster isn't rendered, but it doesn't even render in BTB, not even in wireframe. That makes it pretty hard to position the caster. This is the perfect excuse to include visibility layers as i mentioned in the more recent wishlist thread, like in photoshop, so i can hide collision object, shadow casters at will. It will also help with performace too because as my project has grown fairly big the performance drops off quite a bit, and i've greatly increased the frequency with which i toggle the walls and objects on or off when editing track segments or doing intensive terrain work, and blending particularly is entirely unusable while walls and objects are on. Anyway, i hope v0.9 is getting close, but not so close that it's too late to include layers Cheers!