Add the files used for a stack into the metadata?

Is it possible to add the files that were used for the final stack into the metadata, and display that metadata? I’d particularly love to delete the unneeded images in the front and in the back - sometimes those are quite a few as I like to leave a bit of wiggle room. But once I close the app, the first and last are no longer selected, so I don’t know which frames can be safely deleted.