Yes, absolutely the stem height is important. If you've ever looked at DSA vs SA, the stems are not the same at all. These will be designed to fit the shortest height, probably DSA but some cherry profile are even shorter. That means there will be some modification necessary to support taller stems. One possibility would be to fill the top of the cap with resin or epoxy to the necessary height and flatness for the replacement stem. I can imagine the need for a jig to help with positioning the stem. A similar jig would probably be necessary for artisans as well.
This is all still being designed, I need as much feedback as possible to make sure it will fit everyones needs. The main thing I'm focusing on is whether there will be enough interest to hit an MOQ.