I'm not familiar with the Halycon Cinch system, so I looked it up.
My thought is that once you get your backplate harness properly adjusted, you have little need for any kind of "quick adjust" any more, unless you are drastically changing your exposure protection. I feel that so-called "features" like this just over-complicate what should just be a continuous webbing harness. Extra buckles and cinches just mean extra crap to get snagged and caught up, either in the water, or when donning & doffing.
That was my experience with the Cinch - I bought it, installed it, didn't like it and gave it away. I find that my BP/W with a single continuous piece of webbing goes on and off easily with my dry suit or my 3 mm shorty, even with my shoulder issues. However, I do understand that for some people with more significant shoulder problems, the cinch or even a breakaway clip is a reasonable option.
Halcyon makes a little fabric piece that bolts to the diver side of the pad that I like. It's not for padding, but it's a very convenient place to stow an SMB.