Would enjoy taking a look at your schematic (polish on mine was too much time on a saturday on the hook).
I've switched out the orginal 4D's for 6V Deka for house. About 740 amp hours. We really use the genset mostly in late july and august for AC at anchor. We get 100 plus temps here in the Chesapeake and the genset was an accomatation to my wife and kids. Run it for about 4 or 5 hours after we finish swimming to cool the cabins off and secure it. End up using it 3 or 4 weekends. When we do an extended trip ( a week or more in the summer) will also use it to top up batteries.
We also have an asymetrical that came with the boat for downwind. For our light summer breezes here on the Bay it is a life saver downwind