> ...because humans don't play against engines very frequently, there can be some small divergences between scores on the FIDE Elo ladder and the CCRL ladder…
This is precisely the problem. There are very few games between FIDE-rated players and CCRL-rated “players” under tournament conditions. The question of what FIDE rating a given CCRL rating would be equivalent to has been analysed extensively before and “small divergences” would be quite the understatement: https://talkchess.com/forum3/viewtopic.php?t=59332
In general ratings obtained purely by computer vs computer play are known to exaggerate the differences between computers compared to their performance against humans. This was known and discussed as far back as the 80s.
Ultimately the only way to discover the true strength of “Pentium Pro-fish” is for it to play a large number of games against FIDE-rated humans under strict tournament conditions.
> But if you happen to know a 2700+ Super GM who wants to try and defeat a 2026 chess engine playing on 1996 hardware, I'd be happy to accept the challenge!
Hikaru Nakamura? Has a history of playing chess computers in various odds matches and it could be interesting “content” for his entertainment brand. But really any of them might be interested if the financial terms were satisfactory.