This little turn buckle might work for you for under $2.00.

Seldom i love your Macgyver way of thinking to build a better mousetrap. I was thinking after seeing your video of the turnbuckle like Mad Scientist.
Great thinking and videos you come up with

Thanks Minkpan! Yes, I'd considered the turnbuckle as well and I even have a few I could've used BUT I ruled them out because I persoanlly didn't want to screw stuff in & out every time I went to set them up or take them down. Even the toggle latches could be easily made a little simpler by drilling-out the threads and only use the jam nut.