FACTS can be unposted for multiple cycles as long as the range of cycles are within the same fiscal year.

In this example, the last, most recently reconciled,  Cycle posted shows up as Cycle:92 and can not be changed.
The From Cycle appears below the Cycle and can be changed to any cycle within the current fiscal year.  If you attempt to go past the current year, you will get a message like this to remind you:

This processes single year constraint is due to the next operation - the editing and posting in the GL of the reversing journal entries.  You can only post one year's journals at a time.  Restricting the reversals to a single fiscal year allows for smoother processing.

The tool can be run repeatedly to back up the processing for multiple years.