Thanks for promulgating that warning Bill, a timely reminder to all.
What you describe is exactly how my 54 #154 is configured. It is also documented as such in the circuit schematics in the owner’s manual. Im pretty sure all of my previous boats were also configured in this way. I suppose “battery isolation switches’ do exactly as their name implies - they isolate the batteries. Everything else stays connected together. Best regards Dean SY Stella A54-154 A Coruña