Our keycaps should sit snug enough for normal everyday use on most of the different cherry mx switches (and clones thereof).
We have test-fitted our caps to a bunch of cherry mx variants:
blue, green, red, silent red, black, brown and clear
and to a selection of mx clones:
gateron: red, black, silent black, clear, brown
kailh: box-red (old tooling), speed silver, pro purple
outemu: blue, brown
The caps will have a good enough seat on those switches for normal typing or gaming but can still be pulled off by hand rather easily and might come off during transport if the keyboard has space to move/rattle around.
If you find that our caps don’t fit snug enough on your keyboard’s switches or if you just want a tighter fit than out of the box you can use any type of thin (foil-like) piece of plastic or paper squeezed between keycap and switch-stem to snug things up.
Cut a little square of the material and place it on top of the stem before you fit the keycap. Use a piece of clear plastic if you’re concerned about light shining through the caps.
Avoid materials that are brittle or conductive (don’t use any type of metal foil), parts might break off and end up inside the switch.
Adhesive tapes do work but might leave some adhesive residue on either the switch-stem or inside the keycap cross or both.