Thanks for all the info, everyone! I have to use a carpet runner on these stairs, because the center area is pretty trashed. One had the lip of the stair partly broken and another one had a big open knot. They're not pretty enough to stand alone, but i think they will look fine mostly covered up. I'm hoping i won't regret using the water based stuff, but the part of the tread that shows won't really be walked on. Here are pictures. the treads have two coats of polycrylic right now, and I'm planning to add a third.

Like the OP, we bought our flooring from a full service flooring store. Among other things, we had discussions about our engineered wood flooring choices, whether the manufacturer carried matching bullnose pieces, and if not, what was the workaround. Our engineered floor in Calif. was about $9/sf for the boards, so that’s, I guess you would say, mid grade. But the whole reason to go with a store like that is for their advice, their experience, their leverage with the manufacturers, their excellent Yelp reputation etc. Otherwise consumers can just buy on the internet... So when you buy and install flooring with a one stop shop, the store *should* manage the customers expectations as to quality and appearance if the floor has such significant shortcomings. Does anyone expect a homeowner to think of these details on their own? Our store explained everything and left no surprises. I am sorry for this disappointment for the OP.

My vote would be to match the floor. You asked about matching but without a picture of the existing floor, there's no way to advise.

Can you post some photos of the actual space?