No problems with float plate
Have a float plate on my 2013 M800 Proclimb, previous owner had installed ... I would probably have gone with a more conventional skid plate but rode as-is last season. I noticed only minor snow buildup, did not seem to be a problem at all ... Having no experience without it on there I don't know about the "float" it gives, but the sled was terrific during multiple over-the-hood powder days last season so maybe it helps? It does offer a pretty good first line of protection for the frame and a-arms also. Not planning to take mine off unless I notice an issue this season.
One advantage is that I generally store sled in heated garage between rides, no chance for water freezing to ice and causing trouble. Setup is basically stock 2013 153 M800 with the 2.6 PC track, Powder pro skis, float plate, clutch upgrade, anti-stab, gas can & tunnel bag, etc. This year it gets a pipe, y-pipe, controller.