In reply to im off:
For those routes the schrunds could certainly be an issue by the end of the summer and rock fall could still be an issue in September. You’d need to ask at the OHM but some routes would probably still be doable. You can always ab into the Midi South Face as well.
End of May could be problematic for routes off the Midi as the lift could be closed, depending on your exact dates. Still a fair amount of snow around but the south facing stuff should clear quickly as the sun will be pretty strong. May be consider snow shoes for approaches if there are no tracks!
Also you could consider the rock routes on the Cham side of the Peigne and the Blatiere, which don’t have glacial approaches. There’s a new guide book out for them.
There’s plenty of non glacial granite in Switzerland as well, for example the Salbit.