Keep it simple.
Screw 2 hooks into the root rip, which should also have 1/4 ply plate bedhind the root rib, and just use 3 thick rubber bands. Have been doing it for over 10 years.

I always install the 1/4 inch ply plate before I install the root rib. But on an ARF that didn't have the 1/4 plate, I simply carefully cut a square about an inch out of the root rip, inserted and glued a 1/4 inch play plate and replaced the original root rib piece I had cut.

Works like a charm.

The Hooks I use are approx 1/2 to 3/4 inch in diameter.