I remember a case of recovering a hacked account as recently as October 2020.
The stolen account was recovered using a signed ETH address. There is even a manual or description of the entire process that the owner of the stolen account created. It is written in Russian, but I think it will be useful as an example for the OP.
OP, I think you can do it. Good luck.
https://bitcointalk.org/index.php?topic=5284615.0Thanks for sharing that! I am glad to be proven wrong in this case and that is indeed possible to recover account using ETH address like @Shef198911 did in that case you linked! Maybe that topic about account recovering should be updated so people actually know that signed ETH address is a valid proof of ownership.