There is such a thing known in editing as a time cut. That is you cut from one scene to another and there is an implicit passage of time in which any audience not made up of half-wits can deduce that events not directly linked to the main narrative took place, even though we didn't see them. So long as the framing takes place somewhere between these scenes I don't see a need for revisionism.
The only place one could legitimately alter FotR with this sort of thing in mind is the brief shot from 'Riddles in the Dark' where a younger looking Ian Holm finds the ring. That and I suppose that very early effects work shot of Gollum in Moria.