sigh...
G80 = MX
G81 = MY
Keyboards with G80-XXXX have MX switches, keyboards with G81-XXXX have MY switches.
MX and MY switches are totally different, but MX and MY keycaps are fully interchangeable except for certain modifier keys, where the stem is off-center in MY keycaps and centered in MX keycaps.
All 1.0 MX and MY keycaps are fully compatible.
G83, G84, G86 switches and keycaps are completely different from those.