Hi Russ,
You don't need to actually do the GetProps until the moment when something needs to be undone. Keep the array of TextItems until it is no longer needed. Thinking out loud as well, this leads me to the original question: what is it exactly that you want to restore?
You could keep a safety copy of a Pgf every time something within that Pgf is changed. Then restoring becomes retrieving the entire Pgf and overwriting the changed Pgf with it. Similar for other objects, but as you mention character formats I assume saving a verison of a Pgf on every change inside it should do the trick.
Ciao
Jang