Here’s another suggestion for OGS ranks: Only Kyus
The only 1 dan in this system would be a hypothetical perfect player. It would have an Elo rating of 0. All other players (humans and AI) would have kyu ranks and negative ratings.
I estimate that top AI like KataGo would be about 1k (able to win about 50% of games against a perfect player with 2 stones handicap and reverse komi).
Everybody else can measure their rank by determining the handicap they need to win about 50% of games against top AI that are good at giving handicap, like KataGo. So if you need 8-9 stones handicap against KataGo, your rank will be 9k.