I doubt you find much help on this forum. Most people on here are passionate owners who would rather cut their arm off before renting their RV. Too much money spent and too much at stake for damage. And too personal and emotionally attached. For this forum, Rv'ing is a lifestyle, passionately pursued and a lot invested.
I would check local RV dealers or places that rent TT's and ask them about insurance, or call a few brokers and ask. The only company I know of for commercial RV renting is MBA. You could try there as well. Good luck. I know it's been done, I've seen TT Arbnb's as well as campgrounds that rent RV's on site. Call one of them and play dumb and ask them what kind of insurance they have. Maybe if it's not moving, it's not a big deal. It's renting drivable RV's that incorporate a lot of risk.
