What about instead of platforms moving across lava, you just have lava triggers that turn on and off with certain timers and you have to figure out the pattern and be quick to stay in the non-lava area and whatnot, maybe while dodging projectiles or something to up the ante. I mean, it's not quite the cool factor of platforms floating through lava, but it'd be easier and much more inline with what the engine is capable of. Plus I still think a mini-teleport sort of item would be mega fun. To make it more readable and easier to use, maybe you make two items, one that creates a mini-pyramid or some other indicator where you will teleport, and the other item teleports you to that mini-pyramid, which is destroyed on teleporting. Or you could just make an item that throws one of the existing teleport pyramid forward a certain distance.
By the way, is this just a section of some larger map, or are you trying to do like, a complete trap dungeon crawl kind of thing? Or just a case study kind of thing?