Right now I'm thinking that's a no, since the GG is sealed on a dust proof compartment...but who knows what the future will bring us...
This is probably the best reason not to allow users to change diffusers. The unit, as it stands, produces an extremely awesome image and shows that the engineering team knows what they wanted to deliver in the first place and is confident in the design optics to seal it away and pass it on to the user.
Trust me. Dust in a unit is NOT good. Once you stop down that stuff becomes super-apparent and a lot of the times you can't see it til it gets to a larger screen.