Great writeup with lots of practical utility for real-world use-cases. Really well done. Thank you!
I currently use an unknown brand tactical-style-esque bag I stumbled into at a thrift store that I use as my camp bag when pairing with the Styker XL. It is a backpack, but has straps that tuck away that's very similar in shape to the Hill People Gear Decker bag. It's reasonably well constructed for this use since it doesn't carry load nor take abuse from the trail and off-trail travel (contained by the more robust Stryker XL). It's downside is a little bit of extra weight since the back panel is padded as it's built to be a stand-alone pack. I prefer it due to its shape (true rectangle) and it has a little bit of organization in the form of some outside zippered slash pockets, etc. An unforeseen upside of it being an actual pack vs. bag is the ability to carry it on its own to move camp during a slight pivot.
In my opinion, the best camp bag to pair with Stryker/Stryker XL (and even Nomad and Straightjacket type bags) is a rectangular bag. It perplexes me why there aren't many viable options for bags of this shape. Most dry bags, and even the Kifaru camp bag, are round or oval. This isn't a blocker but becomes somewhat problematic when stuffed—which can occur easily in colder climates with cold weather gear. While functional, these round-oval bags pretty quickly push your load far out from your back which isn't fun when logging miles. There are a handful of duffel bags out there this shape (Black Diamond Stonehauler, for example), but they are weight prohibitive since meant to be stand alone bags.
For certain scenarios, I'm considering the medium or large Hill People Gear Decker bag, largely based on shape. They are similar in width and depth, just get taller. This keeps more of the load on the Y-axis, driving weight to your hips, vs. pushing out the load on the X-axis, which negates the benefit of a load hauling frame.
The downside of the HPG Decker and many of these bags—Kifaru Camp Bag included—is that they are nearly all top loaders or roll tops, which can get a little annoying while at remote camps. This is reduced to some degree that the majority of contents are for camp itself (shelter, sleeping system, etc), but for cooking gear and miscellaneous sundries it becomes a dump bag, which stinks when dark, tired, and fighting weather. And also when repacking camp to move.
To me, something like the HPG Decker bag with a center, side, or U-shaped zippers would be a great solution. I did look at the Eberlestock Super Spike duffel, which is down this vein. It's just too small for cold weather hunts and I'm not familiar with build quality. Or a rectangular Kifaru Camp bag that simply seats better in any of their more modular packs.
Across the board, it's important to remember that each of these bags can push contents out away from your back quicker than you think. This is why rectangular/shallower/taller, to me, is the way to go. I just wish there were more options in the market to fit this use case.
I did something similar to this with a pintler. This is the second trip out so the bag was empty. If it had anything in it it would have been hard to manage pushing weight out that far. It worked really well keeping camp in the dry bag and hunting with a day pack from there.