I’ve got a Streamline bed in mine, bolted down at the rear and then leave the 2+1’s in place unless we need to use the Streamline.
No need to do anything to the rubber floor as the bed is bolted through it.
In the winter I run as a 2 + 3 + 3 seats and in the summer I take the middle row out and run as a 2 + 3 seats.
Personally, and I’m a big lump, I found the RIB a bit flimsy, pretty sure I’d break the 1st foot/thigh section just climbing onto the bed as there’s no bracing under it.