Though I’d share since I there isn’t an off the shelf CCF system that I think is the full package.
Exped Flexmat LW. Trimmed from 65cm wide to 58cm wide and from 196cm long to 180cm. The outer row of indentations is almost useless as they drop the egg pattern from 3/2 to 2/1 so losing them made no difference to support. It’s also slightly thicker at the ends, so removing the ends improves bulk. I also found 65cm, carried on the bottom of my pack, to be awkward and you’d bump into a lot of stuff (doors being the most annoying). 58cm is much more manageable. 180cm long is good for me as a 6’2 side sleeper. Flexmat Plus LW stock is 617g. trimmed to 58W, 180L is 519g.
2) Flat folding mat to lay on to. This spreads your weight on the eggs, giving exta support so that the eggs under you don’t fully collapse. Too thin/low density and it wont spread your weight. I use a Decathalon roll mat which I tuned into a folding mat. This mat also acts as my back panel. Advertised as 180cm x 50cm, mine is 180 x 53cm and weighs 223g (advertised 210g but I guess mine is cut wide). to turn it into a folding mat, I measured, folded and then placed wights on top and used a hair dryer to soften the edges. When it cools, it holds its new folding shape. In an ideal world I think you could make something better and lighter using a thin layer of HD foam joined to a thicker layer of low density foam. Used to be £5, now £7 :)
3) Optional sheet. I use Thermarest synergy sheet lite. As well as being nicer to sleep on than foam and easy to wash, I reckon it helps to trap air, improving the insulation of the system. The sheet also has quilt attachment points that match up with my Thermarest quilt so I never use pad straps. I have the wide sheet at 94g but I think the normal version might fit this system (74g).
On paper the system would have an R-value of 3.6 (2.2+1.2) but I believe that foam to hit r value in real life while inflatables under perform their R-value in real life. Trapping air with the sheet could add an extra 1 or 2 to the R-value.
I’ve had this system out on a few nights below 0C and I’ve been comfortable and I have no problem sleeping comfortably with this system. The Exped Flexmat Plus LW is a bit expensive and definitely flawed but with some minor mods and adaption I think its about as good as you can get for CCF if you need some extra width. The Nemo Switchback looks like a great design but I can’t quite do 50cm width as a side sleeper.
System total is 742g w/o sheet (836g w/ sheet) which isn’t that far away from something like Tensor trail reg/wide + thin light at 594g, which I think could be a fair ultralight comparison.
System could lose 50-70g if you got the materials just right for the flat mat. Something like plastazote HD30 2mm bonded to 3mm Plastazote LD30 or EV30.
