Interesting idea. I've never heard of it, but it sounds like it would work for most of the strips. Using cove/bead with cove side up would complicate it a bit, though.

I tried going without staples, but ended up using a few. I did end up putting some sheet rock screws into the forms AFTER I had assembled the strongback - I wished I had done it before assembly, as you suggest. The are great for providing purchase for a clamp, or as you suggest, possibly a string.