Here are the results of my experimentation.
First thing I tried (to save weight) was to modify a single pillow. My idea was to “quilt” the single pillow by heat sealing part of the center of the pillow. It worked… sort of. I played with various setting with my iron and eventually got a pretty good seal but in the end I came to the conclusion that you could never get it perfect… not like a factory seal… you will always get a leak. If anyone wants to try it themselves, this was the proceedure…
1. Use medium high heat
2. More pressure is better than more heat… too much heat and it just melts a hole… press hard!
3. Use the top of a bottled sauce or juice bottle under the pillow as your surface to press against and a thin sheet of aluminum on the top of the pillow (between pillow and iron) to prevent making a gunky mess of your iron.
As I say, I did get this to work… almost… it has a slow leak where I did my handiwork. Also, I found it wasn’t even very effective in increasing comfort. It helps some because there is a depression for your head… but since it’s still a single chamber, the air can still flow from one side of the “button” to the other.

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Next I tried simply sewing two pillows together using the excess material beyond the factory sealed seams. What you end up with is essentially a monster sized water wing pillow. This worked beautifully. It’s not as good as a stuffed pillow of course… but it is MUCH better than a single chamber air pillow! And adding a layer of foam on top like the Luxury Lite pillow would really make it great I think… for around 2.5 oz (guess).
This pillow is 1.2 oz and it’s full sized. It’s probably 6 times bigger than a typical water wing pillow at the same or less weight! My water wing pillow is 1.6 oz. and it’s TINY.

p.s. I’ve copied this post over in “Make your own gear”. That’s probably a more appropriate place for replies.