A few thoughts on chaps.
The video states at the start that these are field tests only.
To do a proper testing a device must be made that will apply consistent pressure and chain speed. Chains resharpened in between each test and so forth. {The video showed at least a respectable 12,200 rpm's}
How you sharpen your saw and what type of chain you run are also big deals.
Please note that no chap manufacturer has ever guaranteed their product to stop a saw. View your chaps as a great idea, like a seat belt - air bags - hard hat, but by no means a guarantee. Wear them always, but always have a functioning chain brake and always watch that tip and your thumbs etc.
Yes, with any cut that cuts more than a strand or two of the protective fabric, the chaps must be retired. A great use you can give those retired chaps is to finish your tailgate safety with a demo. Attach the old chaps to a log and have your best sawyer lay into them.
One thing you may note is that if you fasten the chaps loosely, the saw will rotate them exposing unprotected log(leg). So if an operator is not wearing a full leg, (360 degree coverage), the fastening of chaps snuggly is critical.
Additionally no repair can be made that sews through the chaps layers. If the layers are held down and not allowed to float freely, the can be cut through easily and are less likely to hold together long enough to jam a sprocket.
Dirty chaps are also a problem. If you have chaps that are soaked in bar oil/grease, be aware that will also hold together the fabric similar to sewing and they are cut through easier in testing.
But don't clean with a detergent with chlorine. Chlorine weakens Kevlar badly.
Now having said all that. The heavier first pair of Labonville chaps sure look like something I'd want on my newer employees. If not everyone.