This is my solution to the chain tension problem
(after spooling my chain once).
I made two small rolling sleds that holds the chains and are have constant tension by a center weight. The center sled is free to move and redirects the line of pull over the top to weights behind. It uses (two) 2.5# weights (not shown) to pull on each small chain sled to keep the chain under constant a pressure. It keeps the chain on the same plane as the sprocket and out of the way of loading a sheet of plywood. I’ll post a video and the 3D printed pulleys to Thingiverse asap. Jon