Also, I know this is all very WIP and it's likely to get fixed anyway, but I have to point out that the main thing that irks me about how lake Texcoco looks is that its water level is too low, and should be more like this:
View attachment 1332609
Since the area around lake Texcoco was relatively flat:
View attachment 1332611
I suspect that the game engine automatically puts all water bodies on the same level, thus creating these weird coastlines in high-elevation lakes, which was also a problem in EU4 which took a while to get solved. I hope this can be fixed. I just hope we won't get reverse mount doom in Tibet again:
View attachment 1332635
And as for the Tenochtitlan not being on an island argument, what I'd see as a good solution is to just disable its building models completely, except for maybe a single mode (fort?) on the island, and putting the capital marker on the island. One day we'll get some DLC with random models in it, like in every PDX game, and a Tenochtitlan model will be one of them. This would genuinely be better than the current situation.