Once my confusion over how to deal with the onion mix was clarified (thanks all) this proved to be an easy, fast bake (in terms of actual prep). My notes follow:
I used 1 oz of the onion water and 9 oz plain water
My egg was almost a full ounce heavier than called for
I used 100% milled wheat, a 50/50 mix of hard red and hard white.
My cooking time ended up being around 25 minutes.
These are tasty and the outside is crunchy. They aren't overpoweringly onion-y, which I'd been concerned about. I think the flavor would be improved if I make a soaker with the whole wheat next time and let it sit in the fridge overnight prior to adding yeast. I'll make them again for sure.