Apparently there are Find My compatible generic tags coming out of China already, and they cost less than $5, shipping included. I say apparently because I’m still waiting for one to arrive and test.
Interesting. Although your link is 11.70$ with 50% off for me, but if you search for “find my Apple” you get many more results with lots of options around 5$
Interesting! I would have thought that Apple would add some sort of tamper-proof hardware authentication mechanism, given how expensive and privacy-sensitive AirTags are.