Since TeX has not designed anything yet, he probably can't say if support would be possible for other boards. The main question would be if Race and K84 (or something else) share the same (or compatible) mounting holes. I really want this to work, so it's probably best to initially concentrate on the Keycool like the OP. They Keycool is a good keyboard, and I'd be happy with that.
If we get enough interest, I'm not worried at all about the designs coming to fruition. TeX knows what he's doing.
A render would be nice.