Ambigiuous ending, sorry.

Last stretch is ambiguous. Hint: All 4 corners are filled.

All symmetrical but ambiguous.

I agree!

Even if you assume it's rotationally symmetrical, and all 4 corners are the same, there are still multiple possibilities. A real letdown of an ending.

It's a real letdown all over. After all, 'solvable through logic' and 'solvable after assuming symmetry' should be mutually exlusive.

Multiple possible solutions. Thank you for the puzzle!

Thanks.

Easily solvable when you know it's symmetrical and the four corners are black.
But still a poor puzzle. What a shame.