Ah. That does make sense. Just slice an occasional thin slot out of the back side of the fascia to snap a thin sheet of plastic into. This would totally work with the stock lens, however:

I don't have a Darkstorm lens, but from what I gather, this might not be possible because Darkstorm mills his lenses so that the fascia sits down into it a little. Otherwise, that's a very good idea. Can someone confirm or deny that the Darkstorm lenses are embedded in the way that I'm thinking they are.