I've done MR's to LGW, LHR, FRA, ZRH & CDG all without ever having a problem. And many times with a stay of less than two hours.
The only time I was ever rally questioned at all was in FRA, and I happened to have a copy of my statements showing that I'd done this several. And no more questions were asked.
Knock on wood, but so far I've never had a problem.