Different keys for different players at the same time

Is there a way to let say two piano players play in different keys at the same time?
(I tried the five years old workaround of @fratveno, but this only works for one drum line. I tried to change the key for the first piano player but then only the upper staff changes the key, the lower staff remains in the key of the second play).
Is there a more “official” way to get separated keys for two players?

The “official” way to get independent key signatures is to confirm them with Alt-Enter, and you will indeed need to do this for every stave.

Thank you @hrnbouma , that helped … I did it some wrong way before. It worked now marking the concerning stave(s), pressing ALT and clicking the key.