I am interested in this as well. I live in South Sapin where it is also dusty.
Is it possible to blow dust off the drivers? Could dust get stuck to the film of the drivers? Or even worse inside onto the contacts?
For a storage / dust cover I tried a glass dome to fit over my headphone stand. It keeps them really clean BUT in Winter the leather cups get a thin layer of white mold growing on them, so not good either.
I might try and create some air gaps to the base of dome where it sits on the wood circular base. It is has some ambient air flow to reduce any condensation or damp build up, it should work?
BTW I hate the Stax plastic covers...