The found set itself is information, and you can easily loose it during usage. Doing a new bad search, closing a window etc.
Of course there's ways the advanced dev can mitigate this (though it's painful), but it's way above the head of the "secretary" which is FMI's number one target.
Moreover, it can even happen to advanced users, working on dirty dev layouts which won't get any of the mechanisms found in the user accessible layouts. And the workaround are slow.
FMI already has already the pieces in place with the snapshot links, I just wish filemaker would automatically store a internal snapshot as soon for each found set change (just 1, or maybe a user selectable number like the history) per window.
If a window has been closed, there would be a restore last closed window in the window menu.
There would be also a restore found set menu in the menu window
of course, all of this completely scriptable, with dev access to the record ids of the found set history.
It would be very useful for the average joe to the most advanced dev