Interesting, I just uploaded the .mp4 directly to lemmy and assumed this to be working. How else would you share a gif/short video?

Pretty much. I'm not even sure if regular USB ports can talk to pins individually, let alone test them for shorts.

Not sure what else, but the thing can tell you if a cable is USB2.0, USB3.0/3.1/.. or just for charging.

I could design and produce a small batch of those adaptors.

Would anyone be interested in getting a prototype and helping to test it?