Agreed, it sounds like UltraLight is the way to go for you. I added a few attachment points to mine and its 1050grams so less than 2 pounds. I don’t think a thicker floor would do much for it other than add weight. A chain is only as strong as its weakest link and with the air-holding tubes still mostly made up of UL fabric, that’s where your failure point will be.
I guess theoretically you could be able to resist slightly more abrasion against the ground at put in and take out, but with a UL upper you’ll still need to avoid the same types of paddling you would with an ultralight packraft.
To me it sounds like a poorer all-arounder rather than improved ultralight, but of course, it might respond to your needs and be just what you want. Let us know if you end up making it.