These straps seem to have potential.
Daisy Chain Straps
I assume you could run these around main tubes or thwarts.
(Possibly even run straps through the tiny loops rather than just biners?)
Yes, I am paying attention to entrapment -- the "loops" I have created through the adjacent drain holes are very small and tight -- not that easy to use -- a fair safety trade off! (they mimic the long line of loops on AIRE IKs, but even smaller. I am open to being corrected for unsafe practices!