Hi Michał,
I just received the following answer from our development team:
It’s safe to add the same file multiple times to a mapping algorithm. Part of why it takes a bit of time to add a bunch of values is that we query each existing value to ensure the new values added are unique. Of course, adding the same file twice will not increase the number of mappings available.
Sounds like you should feel free to add them again as you see fit.
Thanks for being an active member of the community.
Michael