How are you drying your wings post-SV? I've always found it difficult to get SV wings dry since the bag liquid is so full of gelatin it will thicken at room temp. Usually, what happens is there will still be liquid on the outside of your wings when you freeze which will explode in the oil. I always just keep my SV wings in the fridge uncovered, flipping every day. They last up to a week and they get better as they sit since the outside dries out and causes a crispier wing.
If you're doing this in a restaurant context, maybe "washing" the wings in warm fat before freezing would help with the splattering. The oil will displace the water and, once you drop them in the fryer, there should be significantly less splattering. Maybe set a deep fryer up at 120C, then just get a few wings in a spider and swish them around in the oil for 10 seconds or so before laying them out on a sheet tray and freezing.
