When making tilemaps for a game it’s extremely useful to be able to re-use tiles flipped and rotated. If you flip or rotate a tile in aseprite it’s counted as a new unique tile though. So you have to manually pay attention to which tiles are redundent if you wanna have your tileset be fully optimized
If you could place tiles flipped and roated that would be really useful. You could have a good view of your tiles, and still have your real tileset not have unnecessary parts
Is it this new release?
This is available in v1.3 
You can use Space+X / Y / D / R to flip X/Y/D or rotate flips. You can also configure a tileset in its properties to match flipped versions automatically when you use the Auto mode.
In the promo video there is a demo of the flip/rotation:
I have have created a very rough but working export script for aseprite that exports the tileset image and tile location data including flipping.
Also a Godot 4 script to recreate the tileset and tilemap in a Godot Scene.
It works well just polishing it now.
