Hints on how to pack a PCT lack tightly?

Three side straps on each side to pull it tight sounds like a good idea. Hmmmm. It is a rolled cylinder with a thin contact point along the middle of my back (not too thin but thin is an accurate description). That gives my back air but I may give that aspect up for overall tightness. The one compression strap is not for cinching to the back. It's thin. And it runs through the big outside pocket so it wouldn't work that way. Good advice. I'll try to attach pic.

Photos would help– I can't find anything on that design.

You have a common dilemma with frameless packs. They need careful packing to get maximum stiffness and weight transfer; otherwise, you carry the weight on your shoulders, or the column collapses and the pack bows.

Large tightly packed stuff sacks are just like smooth rocks in a frameless pack. You can't get a good column constructed and something will be poking you in the back. You end up with a lot of wasted space, not to mention the weight and expense of all the stuff sacks.

I do use small sacks as classic ditty bags to organize gear: one with essentials like first aid kit, batteries, lighting, etc and another with my hygiene/latrine kit. I also use large light sack for my bear hang food bag. My kitchen kit goes in a big ziplock.

Seeing that you have two pads, you might try one folded against your back and the other used as a tube to form a column in the pack. Take an unscented trash compactor bag and put that in the rolled pad, and put your quilt and other soft clothing that you won't need for the day inside the bag. Twist the top of the bag up and tuck the twisted neck of the bag down the side. That will keep it all dry and allows some variation in size and density. Then add shelter, kitchen kit, food bag, ditty bag with essentials, hygiene/latrine kit, and clothing and snacks du jour. Some of the latter can go in outside pockets if available. If you are using a bear can, it has to go where it fits but isn't poking you in the back.

I got so tired of the fiddling and compromises that I went with a framed pack. I do use frameless packs for day hiking, but the loads are much lighter. The cloud system does the trick there.