I used New England 1/4" V100 as the main hlyd on my SC20, cleated off at the base. It would stretch a bit in the 1st 10 min, I'd release the dnhl, tighten the main hlyd again, and I'd be good for the day. Need a serious cleat(Schaefer jam cleat?) solidly attached. Preferably one fastener into the cast aluminum base)drill and tap?). Also need a solid sheave at the masthead because it'll be under a lot of pressure. I never perceived any issues with the compression, but the SC extrusion is pretty beefy.

Dave