Beautiful floor! I don't think I've ever seen maple in that color. Are the stair noses are prefinished to match? You'd just use the floor boards on the stair, and the nosing to finish? That sounds pretty straight forward to me and you wouldn't have to worry about either the stain or wear layer; so long as the nosing is wide enough that you can attach it to the horizontal of the stair, not hang it off the front of the vertical surface [which can be done, but is more difficult]. Staining to match is also doable, especially if you are matching a wood with a lot of natural variation. With stair treads, you have a lot of unseen wood on the backs to practice on. A good paint center can help, but since the finish is semi-transparent the underlying wood plays a big role and they can't do it as accurately as they can match a paint. I've intermixed different colors from the same stain families for years. You just need to keep accurate records of what each mix is, and use a little common sense-- don't mix a 'regular' stain with one that has poly added, and read the label to make sure there are no restictions-- Minwax Red Mahogany will only accept certain top coats, for instance, so its a poor choice as part of your mix. But using the factory finish stuff will save you all that hassle.

First, construction lumber is a terrible choice for stair treads. The wood is much too soft and open grained to last under any traffic, even light stocking feet. The wood will splinter eventually, even under paint. Almost anything dropped on the wood will dent it and cause splinters feom the dent. Now, to answer your question. Poly is almost impossible to spot repair. Any finish repair will mean recoating the entire tread. That is not really difficult on stair treads, however. Any finish will be absorbed into the wood so much, getting a working coating will be difficult. Reason, the wood is so soft, the fibers will swell and stick up. You would need to sand snooth. The next coat will also be absorbed about half as much. Several coats/sandings later you may have a workable coating. W#hich will quickly be degraded by the dogs feet. I'd recommend the carpet now. Will save a potential splinter in someone's foot---including the dogs.

Before you go cap treading its better to first understand Run and rise along with FFT. Finished floor thickness at landing and adjoining levels along with maximum nosing compliance.. Theres a lot of handymen that will gladly put you right out of code compliance while taking your money and installing topical cap treads. Your local municipality should have clear staircase compliance on their website or in office.

Thank you! I do have photos, but the floors are covered with ram board to protect them and I have not done the railings yet, so the photos dont really show anything. In hindsight I should have taken more photos prior to starting the work. The stair nosings on the landings have started to sag & slope so initially I only wanted to jack them up a little & install shims, but quickly realized that there were more issues going on here, unrelated to my stain color question. One was that when they set the treads, they were about 1/2” away from the wall, leaving these strange gaps between the end of the tread and the moulding it butted to at the wall. It was very difficult to clean and unattractive. Im also adding a much deeper & thicker moulding up the wall to allow the treads to appear closed ended to the moulding.