8x8 solved it seems

https://techxplore.com/news/2023-11-japanese-scientist-conquers-board-game.html

Here is the actual paper: https://arxiv.org/abs/2310.19387

Found 1 typo so far "wealky" should be "weakly"

Better than 'weekly'! ;-)

Another both colour optimal line seems to be f5d6c3d3c4f4c5b3c2e6 c6b4b5d2e3a6c1d7e7f6 a4e2a5d1d8a2a7c7c8b6 f1f8e1b2f3g2f7a3a1b1 g3e8b7h2g4g6h1g1g5a8 b8g7h3f2h8g8h6h7h4h5

For a "both colours optimal line", is it enough that each move is one of the drawing moves or are there other criteria ?

All drawingishly (maybe 75% all are drawing at a guess)

Does tthis mean the only way of checking for an error is to solve it yourself from scratch?