I agree! I spent hours thinking about that and have not yet come up with a release I like. You will notice what I said in the write-up, "I am not completely satisfied with the pedal arrangement . . . " I didn't even put finish on the pedals. It works but is too flimsy and doesn't fit with the overall look of the bench.
In operation there must be a bungee or flexible connection with the ratchets which don't release until weight is temporarily removed but it must be light enough that the pawls still engage by gravity. I have a couple of other configurations that I am working on.