Thanks for posting this video, I found it extremely interesting !!
Anything to show us about canopy seam strength ?
How does the LE seam strength compare to the strength of the Dacron fabric ? If the Switch seam construction is 90% or more of the fabric strength, then you're there, no need for any further improvement - well done.
Which side of the seam failed, the fabric on the side opposite the fold ( what I call the flat side of this J-seam construction ) ?
Were any test made of a double-Dacron-layer J-seam without the outer webbing cover over the seam, as a double-layer J-seam is also a pretty common construction among many kite brands. This would show whether or how much the webbing contributes to seam strength.
Warning : it gets technical past this point, cool dudes hit the back button, techno-geeks read on ....
After 2.5 years in repairing kites full-time, I have not seen any LE seam failures caused by fraying of edges of the Dacron fabric. Which isn't to say it doesn't happen, just that i have yet to see it happen. I'm sure factories are using laser CNC cutters to form the LE fabric panels and this cutting process fuses the cut edge very well and limits fraying. LE seam failures that I have seen are either stitching failures or fabric tearing at the stitching holes. So IMO any strengthening of the seam from the webbing covering is a result of increased bend radius for the LE fabric as is wraps 90-degrees around the outer layer of webbing on the flat side of the j-seam. Because the webbing is typically loosely-woven and soft, again IMO it does not provide as much stress reduction on the fabric as would a much stiffer ( but harder to fold ) tightly-woven webbing.
Similarly, I believe putting the extra strip of Dacron on the outside
of the LE fabric would maximize its utility, helping increase bend radius for the fibers in the main panel as they bend 90 degrees around the seam edge.
Would love to do a little design-of-experiment project on LE seam construction, but must away and fix some kites.
Huge KUDOS and props to Switch for doing real work to define and improve kite construction !!!