I wrote a while ago that I didn't think that Partition Change Tracking (PCT) fast refresh was worth using, because eventually something will cause the refresh to fail and then, for various silly reasons, you can only get PCT FR back by completely rebuilding your MV in one shot. This is not a practical endeavour in many cases, hence PCT is not worth so much.
However, it has now occured to me that if one kept a backup copy of the data in the PCT-based MV, even if it is only as a regular table, then in the event of disaster such a table could be brought up to dat with respect to the master tables(s) and with the correct MV definition placed over it temporarily the complete rebuild of the PCT-based MV could be rewritten to effectively be a full table scan of this backup. that ought to be more achievable I suppose.
It still seems like a lot of trouble though.