I really appreciate the effort put into this in the OP and elsewhere. This was certainly a subject of interest to me in the 2019 game where I thought the AI was quite slow on some circuits compared to others. That said....after making it half way through my first season I'm leaning to the side of 'it's not the AI that's inconsistent from track to track, it's the human' for the 2020 game. Even Austria.....
I found my 'base' level by spending plenty of time practicing at Spain and also tweaking setups so that I'm dialed in, and then setting up a grand prix weekend and finding the AI level that had me running at a very similar race pace (same compounds, very similar lap times in clean air) to my AI teammate--96 base level. My very qualitative thoughts on AI pace after completing half a season (100% length, no assists, Renault w/ Ricciardo as teammate, all races at base level of 96 for AI) --
I'm a bit faster than AI at China, Netherlands and Austria;
My race pace is very similar to AI for Bahrain and Spain;
I'm a bit slower at Australia, Azerbaijan and Canada;
I don't have a great read on Vietnam or France as the race conditions were crazy, but I suspect I'll be very competitive with AI at my base level;
I hate that obsolete tin can that somehow poses as an F1 circuit. It doesn't matter what AI setting I use as inevitably I'll bust the front wing and spend the rest of the race stuck behind a Williams.
If you were to ask me, without reference to AI pace, which tracks I feel most comfortable / consistent and which give me the most problems I'd say that
China and Bahrain are easily among my favorite few circuits in the game. Zandvoort has the same sort of fast / flowing feel that I really like as Brazil and I've always done pretty well at Brazil in the game;
I know Spain and Austria as well or better than any other circuits. I can push the limits and run consistent times on these tracks at least as well as anywhere else;
Australia and Canada both have multiple corners which give me fits. I've never felt like I could put a complete lap together, much less string together multiple good laps;
Azerbaijan is a kind of a close quartered clumsy street circuit and I don't care for those too much (especially that other street circuit that's barely fit for go-kart racing);;
So the point is that I'm quick relative to the AI on tracks I really like and feel very competent and I'm a bit slower than the AI on tracks where I have some big doubts in my head. That seems to be on me, not the AI.