I find using a stiff brush(small kitchen type) on the BBA helps to keep it under control somewhat. requires more work that way but if I keep the main stuff gone it just eventually does not come back. use green Brillo type pads on leaves to rid there.
Maybe some top cover plants? water sprite can help until BBA is gone, and it grows fast pretty easy to come by, someone here might even just give you some for shipping if you can't find it local.
Really nice setup! Hope it continues to do well.