So, if this is required, you can't send to, say, your custodial account at Coinbase?
Is anyone keeping track, using on-chain analytics, of how many people are doing this idiotic EU "satoshi test"? E.g, Kraken describes the procedure here, presumably other exchanges use variants, which makes for great fingerprinting.
https://support.kraken.com/hc/nl/articles/what-is-a-satoshi-test
Discussion
For sending between custodians (VASP) there's a separate process. How exactly they know which destination or origin address is which other VASP is a can of worm I don't even want to look inside of.