Received answer from Sterling Langrell. Thinks it is a manufacturing defect. Sending another set out. Score 1 for Vans customer service.

I like about a thumb's width. Of course, it depends on the size of your thumb....

I used the same "rule of thumb" giving a final edge distance of 3/4" which seemed like a lot, but then it's nicer to have the space when things get jammed up in there over time.

Thanks Paul.... good tips.
Have gone to flat white, primer in rattle can. Gets used often it seems.

Well, per Paul I guess the new gappage is 3/4"

New pants!
 

Just received replacements. WAY more rigid. Now I can open the clearance up to "1 Thumb" per Paul's suggestion:D

excellent! Glad you asked about it and got some input.

The power of the Forum. How did planes get built before the internet?

Hey, don't turn this into a thumb-measuring contest! :)

I don't see the calibration sticker on your calipers!