It won't work
The Jabsco 37275 was my wife's demand. She has her mind set on it just because it’s easy to use and looks nice. I gave up trying to push practical solutions on her. Some women just don't/won't understand what is required. With a gross weight of 40,000 to 50,000lbs, the weight of the Jabsco shouldn’t make that much of a difference.Nothing is written in stone at this point. The engine room is next to the master cabin and the second head is within 15'+/- of the engine room.One tank the in the center of the engine room seems to be the simpler way to go, but again not in stone. Reading the plumbing posts on the Lats & Atts board makes me think that putting a holding tank of say 30gal in the engine room should work. The question of the value of the Electro Scan vs running out to dump the untreated tank is also a consideration.As, I am the one building the boat from the ground up, the tank can go just about anywhere.The other link you speek of is not working at this time.Leonard