UK Puzzle Association

I'm starting to like Heyawakes but I also feel like I keep getting to a point where I just have to guess and hope.



This is Tawan Sunathvanichkul's Heyawake from his lovely Tam Box Bulletin (issue 8). I've worked it through to nearly the end. Am I supposed to guess or is there something I can do here to finish it logically?

R5C5 can't be black or it almost immediately fails (by connecting the black cells from top to bottom). It looks like it should fall out quite quickly after that.

Yes, that makes sense. I think looking for those chains which connect to the walls is the technique I’ve been starting to use more.