No mounting stem meaning they are essentially entirely useless (they won't go on your keyboard).
Yeah, so that's out.
You've got some ambitious ideas rek55, but there are many limitations.
So I'm discovering. But the best ideas are the ones that rub against those limitations, eh?
Those keys are by QWERKeys, and the good news is they are open to group buys. Not sure what their limitations are in respect of colour, however. Also, making those keycaps with sharp corners will not be possible. This would involve the creation of an entirely new mold which would add CONSIDERABLE cost.
Yeah, I'm going to contact QWERkeys next. I thought that the square corners might not be possible, but shoot for the moon and all that. Probably especially since they are all different profiles. Even still, I think the "b-series" style is better for these than normal solid blanks.
Another option would be to have the keycaps painted black and then have the paint etched off to expose the square. That would probably be the cheapest option, but I think that I'd rather deal with the tradeoff of losing the rounded corners with the B-series.
But it seems you're leaning towards SP anyway, which I think is a good move since they are very receptive to group buys
SP was just the first I contacted, but it doesn't seem they have the ability to execute on my ambitious plans.