A long, long time back, there was a big thread about a series of sort of little platforms that would go on your switch stems.
There would be ones that would fit on to Topre, MX, Alps, and maybe even BS, however all of the tops would be the exact same sort of shape.
This would allow for universal keycaps that could be placed on any switch you wanted.
I don't have the connections to make something like this happen, but maybe the rest of the folks on GeekHack can work together to make this actually be a thing.