This tool is **SO CLOSE** to being exactly what I need for my game -- but I really need rotate/flip options on the sprites when I draw them in the better rule tile editor. My tiles are symmetrical, and I'd rather not have to rotate them in photoshop when unity is quite happy to rotate them (since it means re-doing manual physics shapes, etc.). Any chance of getting that feature?
If you're not using the preset blocks feature, you could actually set rotation the same way you could set it by default. You just need to a tile with the tile inspector tool (E for shortcut) and clicking the center square in the neighbor positions.
I have to admit I actually forgot about this when creating the preset blocks, but I can bring back the option with a quick patch.
So a fix should be coming in the upcoming days.