[Steve B.]

I suppose there would also be no time to add the song(s) to a special setlist? (for later review)

Also, isn't there a 'song history' feature somewhere in the app? I seem to recall a previous discussion about it, but maybe it was a feature request.

Yes! The 'Recent' tab.
You could clear it before every session, then you would at least have a short(er) list to review for changes 'the morning after'.

It seems to me that would be quicker (since it's automatic) than making a special temporary copy.
At least it could be a workaround for the time being...