Try Macrium Reflect free version, it works great. There are no hidden files in BI4 or BI5 clips.
In Blue Iris version 4 you would turn off hi-res alert images by unchecking the "Store alerts as hi-res files" option on each camera's Camera Settings / Record tab. Interestingly, the Blue Iris version 5 help file gives the same instruction but that option does not appear on the Camera Settings / Record tab (see attached image).
Edit: The "Store alerts as hi-res files" option is on the Trigger tab in BI5... help file needs to be updated.
It sounds like the big mistake was not assigning the old drive letter V to the new HDD before turning Blue Iris back on. If you had, then it shouldn't even have needed the clip DB to be repaired/regenerated.
No idea why the clips don't return, though the alerts are gone for good.
Not head of it but anything that relies on MS System restore points for references (from wikipedia), I would steer well clear of. One of the beauties of Storage Craft's solution is you can do hardware independent restores so you can change your entire pc and restore to new hardware and you won't encounter any driver or windows tied to hardware issues. That said, it can be complex as corporate level.
I wouldn't expect there will be hidden files in clips themselves, but once you start moving program files around you can encounter a whole load of issues. Not the same as moving database folders.
I know, that was my point... the "Store alert images as hi-res files" is not on the Record tab any longer. It is now on the Trigger tab but the Help file still refers to it as being on the Record tab.I can’t see that option in the screenshot?