I get to spend about 50 nights a year in a swag, and as I'm getting even more ancient comfort matters, especially a soft mattress.
I have discovered that an exped megamat 10 air mattress is a particularly good thing under the swag. I don't like it in the swag as its too hard/too big to roll up. Works nicely under the swag. Also have a 50mm foam mattress in the swag, as well. The exped mat is nice, much better than the oztrail one I used to use.
One problem is that the mattress is a touch narrower than the swag (mitchell king single ), which means that the ends of the swag poles (if thats the term for the curly metal things middle and both ends) still sit on the ground. This reduces the headroom in the swag by ~100mm , or however thick the mattress is. Which is a big fraction of the available space.
My solution is some nice plastic bowls from the local IGA. Maybe its a noodle bowl. $5 for a set of 4. Drill a couple of slotted holes in the bottom , loop through a reuseable cable tie, and that sits under the pole to lift the swag. A couple at the head end, tied off to the swag pole ring keeps it in place. 2 more in the middle seem to stay there all by themselves. My feet don't need more headroom.
Cable ties through all 4 keep the bowls nested together in the back of the vehicle too. And in that nice shade of pink - nobody is going to nick them.
