You may want to adjust the substrate level so that he can burrow enough to feel safe but not disappear completely.

Mine is super chill, so I have no problems about nudging her out of her burrow when it's feeding time, and she doesn't seem to mind either and eats normally. If it won't stress him too much I don't see a problem with unburying him to eat, but if he freaks out when you do it I'd say no.