Agreed, the thin snow around the Gendarmes makes for a substantially more difficult climb of Casaval. Obviously the trick is getting the right weather window and snow coverage.
I have climbed it a couple of times and it is safer with deeper but more firm snow along the ridge. One time was in March (overcast, minimal winds) and one time was in May (clear skies, no winds).
This year just never got the right amount of snow in my opinion. I am planning to climb it again maybe next winter.
Thanks for your report.