I now have keyboards with so many different layouts (Belgian AZERTY, Franch AZERTY, Dutch QWERTY, US QWERTY, Italian QWERTY, German QWERTZ) that my typing skills are in serious peril. I might follow your suggestion.

BTW, stickers can really work, but need work. The trick seems to be to make the stickers just slightly smaller than the keycaps and apply ample amounts of sealant/varnish. Obviously, this cannot be done with the keycaps in place (or rather, it cannot be properly done that way).