It seems to fit on my R7 about the same as it fits on the R3, if that is any kind of answer. The shape of the body surrounding the hotshoe is similar enough (it's not just a matter of fitting the metal shoe itself). Trying it, I think it holds onto the R3 a tiny bit better than the R7, but I'm sure it would eventually fall out of either one at some point and be lost.
The R7 cover, OTOH, just fits into the shoe itself and will probably fit any Multi-Function Shoe the same way. I don't think it would stay on either camera for five minutes.