Both are great choices! Our last meal at Boma was breakfast, March 2020, 1-2 weeks before Disney shut down.
Our family likes to have a late breakfast around 10- 10:30 AM, that way lunch and breakfast are done and easier on our dining budget with 2 meals in 1. .
Dinner is a great option too, so many wonderful items to try and taste. Tough decision .
I have been and continue to be quite harsh with WDW and Harmonious. But, give credit when due. SE and the lights look awesome. When I see something this cool, it really makes me scratch my head how they ruined the views inside and around lagoon at WS.