Sorry it took so long to get back to this again. Work keeps me busy, but I'm sure you know how it is. Okay so I think I can finally point out where the "blob" tileset fell short for me.
Image credit (this is a great page talking about tilesets btw): https://www.boristhebrave.com/2021/11/14/classification-of-tilesets/
As you can see, none of the tiles in this particular set are corner-only tiles.
So for example, say that my auto tiler rendered a map, and I take a snapshot of this square pattern of 9 tiles, wherein X represents a forest tile and 0 represents some other terrain:
XX0 0X0 00X
If rendered using only the blob tileset, it comes out like this:
But using a 256-tile set where I can specify that corner connection, then it comes out like this:
This use case comes up constantly in my map gen and it comes up a lot more natural with the 256-tile set.
Hope this finally cleared things up!