Double Layer that acts as a weathershield.
Have not seen a double layer live. Not sure if this modification is structurally possible: Replace the outside layer with a waterproof, but breathable built in weathershield with the ability to open or close off the head and foot ends plus allow some tension adjustment. Hot nights open up the ends, loosen all the tension to allow max air movement. Moderate nights seal it up. Cool nights hang the UQ, loosen the tension to avoid compression and adjust the head and foot ends to regulate temp.
Been using the 1.1 Single with the JRB WS2. HH ocf/sb and JRB UQ depending on temps. Works nice, but an integrated WS with side perimeter seal specifically cut for the BB would be simpler, cleaner and maybe overall lighter.
Plus another storage "shelf" when not needed to protect UQ.
Momentum body, Spinntex outer layer with nylon breathing panel. Lighter? Maybe noisy, definitely more $$$s.