There is nothing wrong with feeding during a shed, unless they won't take it. Boas are usually awesome feeders, and I highly doubt he'll refuse it, shed or not. Out of my nine snakes, only my BP refuses to eat during his shed cycle.

It's funny about the shed aggression thing. It makes sense that they might be less secure because they can't see, but personally I've never had any of my snakes try and bite me during this time. In the future if your worried about moving him during a shed, you might have better luck if you just avoid fast, sudden movements. Good luck!