I have had some success using hidden special endings to implement things like p-f markings in repeated sections. This is a common occurrence in Sousa marches. There are other uses for this technique, as well. The only real problem I have had with this has been inserting special endings within slurs. In this case, the slur gets broken into two parts.
If this is not a well-known technique and there is significant interest, I can post some examples.
Not sure how "well known" it is, but I use it a lot.