I called Rob and asked. He said I can sand it down but he can also send me a plastic part on my next order. I don't think he has them listed for sale yet. Our call got dropped before I could chat too much.
Probably at some point, I'll get a couple of the plastic inserts, just to have for spares. They're not something I really need though. I'm not one for washing out my REOs. I'm pretty careful about not getting juice inside them to begin with. But if I did, I'd likely take them completely apart anyway.

