maybe one could add a "fake" Parking Position/Gate with minimal diameter preventing any aircraft parkig here. There the User-Aircraft could make a stop and "call de-Icing"?
While I'm not entirely certain, I think that'd be to difficult to do as it would have to be done for EVERY airport in which GSX is used, which, as it is going to be a universal product, is not feasible
that was certainly not meant to be an "universial solution" - just for the airports you use (and where there is some need for de-icing).
But let's hear what "the makers" are telling us about the idea ;-)