Nice! Thanks for putting this out.
Going to add to the collection but with reservations and some mixed feelings. I've felt the same frustration - and spending the resources to convert to city (typically toward the end of an era when you're in a decent position to invest which then means you're racing the clock to get a return at all,) just to get the specialty districts for historical flavor seems too high a cost. So I've told myself the head canon/RP was that the biggest cities of the earlier era would be the ones to truly reflect the great civilization of the time and have those cultural standouts. Whereas any ole' Town of the day would be lost to the ages IRL (at least here, we keep the settled spot). So it feels a bit cheaty, but I love flavor/RP so lfg :D
Does AI prioritize well?
Your head canon certainly makes sense as well though!
AI was definitely taking advantage of this mod in my Antiquity Age test game. Generally, simple stuff like this that makes use of the database is very AI friendly. Let me know if you see any issues though.