Just a little update on my experience with Universal Control. While I do not use it every day, I do use it ALMOST every day. I find it quite reliable and hassle-free (it has remained frictionless as I’ve described above, with one minor footnote). It is tremendously helpful to me to have available. Universal control is, for me, gradually moving into the “big deal” category.
My one footnote about frictionless-ness is that sometimes when I connect, the iPad is put in a different place in the sequence of windows. It does not make it more difficult to work with, but it takes a moment to re-orient yourself to, for example, the iPad being toward the left of a certain display rather than the right were I set it up initially. Minor inconvenience, but it’s probably a feature: the Mac detecting where the iPad is in reference to the other displays and putting it in the seemingly most appropriate place in the sequence.