Andvari,

You give a good (and simple) example, however the model (or portion of the model) you show is ideal for the kind of work you are talking about. However, not all corrections (or reductions in poly count) are that "soft" on the UV map. Some additions of edge loops or some deletions of vertices will traverse UV edge BOUNDARIES and this will royally mess with the UV map. I think you know what I am talking about, but I may post some images later today on this.