I'm not convinced that acts as 16:1. I'd bet if it was hooked up to a ruler, you'd only see 8:1 (Pull in 8", and see if sail comes down 1"). The blue line probably doesn't move in the center block as the two top ones on the sail come down evenly. You could add two jam cleats at the center or on the sides of the mast (typical H20 setup for a cascade 8:1 system), split the blue rope in two, then "preload" the blue ropes. As you note, you use up a lot of travel to get the thing hooked up. Other solution is ANOTHER rope to pull the sail down and hold it and then hook up the blue ropes. I'll try to post a sketch somewhere.

Chris