They should sign an ethereum address to reduce ambiguity
(Any crypto asset address is fine, even PGP is good enough for this but PGP had 25 years to make that user friendly and common but failed, and cryptocurrencies made signing software more prevalent and uniform wayyyyy faster)
Remember when satellite.earth "pioneered" this idea for their platform? (not ragging on them but some of the content posted on there were insightful and unique)
You can literally generate any public key / address hash that conforms with a blockchain and sign it and anyone can verify that you therefore control it
This has zero crypto assets involved and has no trail of assets so what are you talking about? If anyone sends funds to the address hash the owners can just tornado.cash it and withdraw it somewhere else with an instruction sent over the relay with no prior link to the funds or address. Its perfect right now. But what do you perceive?