oh it has that thing. that someone mentioned. only, i don't remember how it goes. i will try.
YES i remembered it and got it!!!
Darn it, I feel like I should be able to tough this out without greens or a guess, but I just can't quite remember well enough.
At the choke point, 31 cells filled, notice how placing a 5 in either of two cells in the middle block has no effect left or right, but does have an effect up and down. That must mean something. But I can't figure out what.
No, wait. It doesn't have any effect up and down either.
...well, not down, anyway.
Did it! No green, no guess. The secret this time, working with the aforementioned cross-skews, was that I found a cell that was the same with either of two possible inputs. So I just set that cell and the rest was easy.