Well there are actually a lot of new maps being made by a few people for WGRealms 2, and I've already made a mini-episode (it was a big map split into 2 maps) which still needs some polish. But I'm also thinking this could be yet another map for the TC, probably separate due to it's gameplay, which you'll see will be fairly different to the rest of the TC when it comes out.
TROR doesn't crash or lag (unless you're making a huge level, but if it was that big it'd probably lag anyway), although it can be a bit glitchy visually speaking. The 8-bit renderer is fairly ok, polymost is horrible, but polymer renders TROR perfectly. So you can make any kind of TROR and be certain that it will at least work in polymer. If you want to keep it compatible with classic/polymost, then there are certain limits, things you can't or must do to make sure it doesn't glitch.