Gaseous - appropriate name for this discussion - it's NOT really all sound advice so far. PC-6 admits he/she is a fixed wing person. FW - no carb heat guage, whereas helis do. And whilst FWs have EGT guages, helis don't (generally)
It's only safe to say - look at the guage regularly, apply full carb heat as instructed by your POH and don't muck about trying to second-guess the designers. Of course I don't give a damn for your safety - just don't do your experiments over my patch!
It's all very well playing games in a FW - you get a second chance if the engine cuts at altitude. But you won't get that in a heli - the only thing that will get the ice out will be the impact with the ground as you get the auto wrong.