clove hitch a pair of descender rings to each rope just after the tarp prussic. Use a pair of 1 in Harbor Freight straps modified by cutting off the buckle and sewing or tieing in in a loop. You can thread the loop or use a biner or Dutch clip to start. Garda Hitch works. If you do not like that try whoopees to the rings. If you don't like that ...
When you get settled on something you like you can shorten or replace cords without screwing yourself. Assuming you ever get around to it.
Free advice worth what you paid for it. ;-)