We tweaked the BA Hidden rule to Dug In = hard cover (+2 to hit) with all defenders foot squads on table at the start being Dug In until they move. We used the BA Reserves Rule as is. Attackers take an objective by having troops within 3" of it but no defenders within 3" of it at the end of a turn.
The FOW mission (with a few tweaks) worked fine. We did find one problem with BA used for large team games - in normal IGUO systems multiple players on the moving side can do a lot of stuff concurrently, but this is not possible with the BA command system where you have to do one squad at a time, thus large multiplayer games can take longer than one might like.