I ran to REI and Wally World at lunch. If all tests out right at home this evening, I'll carry the Outdoor Products (Wally World) pouch and a Sawyer one as a backup in the Smokies this weekend
The Outdoor Products pouch has taller threads than the Sawyer bag, but it does seat on the input seal. I grabbed 2 (green ones) at $3 each and will do my best to see if I can get it to leak while testing.
I also ordered a Vapur
"outie thread" and a DCI The Water Bag
on Amazon to test with the squeeze filter. I'll report the results.
I have a Vapur
"innie thread" at home that was previously used to bring Vitamin W on backpacking trips.
I'm excited to test if it will screw onto the output end; might be able to have a no-hose gravity feed system if it fits.