I don't know how this would work with the Home Depot line that you have but you may want to give it a try as an adjustable ridge line.
Attach a prussic to the ridge line and nearby tie a loop into the ridge line. Connect the loop to the prussic with a carabiner and then slide the prussic towards or away from the loop to change the overall length of the ridge line. When there is more slack between prussic and loop the ridgeline length will be shorter.
If the prussic didn't work you could tie a series of loops and join different ones together with a carabiner to vary the overall ridgeline length. This would only give you big jumps between "settings" however.