Can you make everything an auto tileset variation so that I can have a tile that has a full corner, or another tile that has a full indent? Tiles with borders that require 2 tiles minimum are very limiting; 9/10 times it can be converted to a 1x1 border but has more rule cases. The rule settings for these are about 14 rules per sprite sheet so I believe it'd be 14 + the base tile aka 15 tiles total needed to be made per biome type. There are also no transition tiles for corner tiles.
are you able to make the art follow this rule set that I published? I managed to get a working version by expanding the tiles to be 32x32 instead of 16x16 & just followed the cases of that image that I showed you & it took me about 2 hours to get the first one done then every other one after that took about 30 mins since it was just paint bucket tool. Its not the full thing & isn't laid out in a pretty fashion but you can use this as a reference.