Replaced with Blue Seas ON/OFF switches. For years I've been telling crew 'engine to A' or 'house to Both' - change makes things much simpler aboard.
First 'overnight' boat had an A/B switch, and I wasn't crazy about it but it was all I had. Present boat started with the same system, and I still didn't like it. Finally separated the house bank and the start battery (but kept the A/B switches for economy). Finally, a battery system that I'm content with - took me long enough!