As soon as I saw this, I thought of Aerospace applications. Especially things like engine mounts, landing gear assemblies, etc. The expensive but few safety critical fasteners.

I saw it the other way, relying on spring pressure isn't wise from a safety perspective and when it fails parts are going to fall into other parts etc and torques are pretty high on stuff like that which makes me wonder about torque limits on this gadget. Also there's no specs on stuff like sideloads or impact loading or anti-corrosion plating. I'm kinda mystified how this thing could work if cad plated without scraping off the cad plate, so ...

Where I do see it making an impact, is "every gram counts" and if you took every washer and lockwasher off an instrument panel and replaced the nuts with these, you might save a small but measurable mass, which translates directly into a small but measurable increase in payload or range or lower fuel consumption or performance. Even on a small plane this might be a pound or two, but imagine a giant jetliner and it adds up to a respectable mass, probably financially a good idea... if its ever aerospace rated.

Note that there's kind of big gap between being listed for sale on a foreign web page with no documentation at all and no specs or datasheets or certs, and being COTS at a place like "aircraft spruce and specialties". For laughs I went there and the price to beat for certified aerospace grade locknuts is like 48 cents a piece, so I donno if this new gadget can compete in the aerospace market at the typical 100x price markup... I mean sure saving weight and fuel is cool, but not if each aircraft certified nut costs $500.