I’m currently investigating a very similar use-case, where I’m wanting to use ProseMirror as a component of an editor for a more complex document model. Has there been any progress on this? I was thinking exactly what @marijn said last: if I could get some kind of event notification whenever PM adds a history entry, then I could simply record that in my global history stack and defer to PM’s own history methods when appropriate.
I was also wondering: If I preserve the Doc and History from a PM instance which has been destroyed (by navigating to another screen), could I create a new ProseMirror with that Doc, do pm.history = oldHistory, and have it just work?