My guess is Boma must be once for breakfast and back for dinner. I'd imagine those are very different buffets. Our ADR list is also final for our 5 day stay:
Narcoossee's (EW parade and Wishes viewing)
Chef Mickey's (bfast)
Boma
Hollywood & Vine (Fantasmic)
Seafood eating vegetarians, with a 5yr old so I figured buffets give us a good chance to eat enough and get a variety. Wanted Coral Reef, but wouldn't trade any of these.