I fly microlights and EASA aircraft, with gaps in one or the other from time to time.
The conclusion I reached some time ago on this is that...
(1) It's probably legal, but there's no definitive statement to prove that.
(2) It's stupid. I can think of no good reason, if I've not flown the type or class for that long to not fly a few circuits to de-rust myself before flying with pax.
G