This seems like a bit of a bug:
I have multiple pup_save*.3fs files:
pup_save.3fs (whatever experimental crud I'm in the middle of munging)
pup_save9.3fs (my "regular" file, which I hope NOT to mung)
pup_save9B.3fs (my backup in case I do mung)
I tried using
Menu:Utilities:Resize personal storage file
and, to my surprise, it modified not one, and in fact not three, but just two of the above files: pup_save9.3fs (which I was actually booted using at the time and hoping to resize) AND pup_save.3fs BUT NOT pup_save9B.3fs.
Don't really have anything else to add. Hope this is useful