Whoah there Sonny, I just gave my opinion. I've owned a Jam (and several other GoLite packs) and didn't care for it. It fit just fine, but the suspension sucked, ego my little rant. I haven't looked at the new ones, but if you can remove the pad non-destructively, what is all the drama about? Pull the thing out and try it with the RidgeRest. I'm sure several folded layers of RidgeRest will give you a stiffer column than the single foam pad.
The caveat is that the RidgeRest won't be captive in a pocket where it picks up weight off the shoulder strap connection and transfers it down to the waist belt, although a single layer of CCF foam isn't going to transfer much weigh before drooping. Careful loading is the trick. A stiffer frame sheet or stays would be the real answer.
No need to get personal or defensive when you get free advice that isn't derogatory towards you. If you don't like my advice, don't follow it! It's a forum, where people *discuss* things. My HUMBLE opinion is that frameless packs suck big time :) Best of luck with your experiments!