The thought of 'preview selected sprites' didn't occur me... I was thinking of previewing slices sprites altogether.
I guess that would be neat as well.
Yes, unfortunately this example is extremely weird.
I started to wonder If It would be possible to make splits with custom rectangular/square shapes.
If I have an atlas that has irregular pattern (sometimes square, sometimes rectangular) then IT will be nearly impossible to split It properly.
Here's an example.
