This would not be a first, see arXiv:1909.00177
The citation (which I think follows the best practice) is
 Fedja, Communication on the MathOverflow website (2018), available
online at https://mathoverflow.net/questions/125861
The citation (which I think follows the best practice)
Indeed, that was a good way to handle it :-) The priority here is, as I said many times, to give the due credit to MO and similar sites that facilitate the free and efficient exchange of ideas whenever possible.
As to myself, my name is neither really famous, nor totally unknown, so I'm neither hiding ...
From the FAQ post on migration: What is migration and how does it work? (in the section "Anything else I should know about migration?"):
Comments on the question that link to the homepage of the target site will be deleted. This is to remove redundant comments that tell the author to post on that site.
It is consistent with the linked post. In this case ...