Request Import To Gallery From Thread Only Imports Post Attachments, Not Embedded Gallery Images

I'm trying to run a photo competition where users submit all their images to a thread, then at the end of the competition time I import all the pics to a gallery.

Then everyone can vote on the best by liking them, we can then sort by the most liked and find the winners.

The problem is, that in the competition thread some users have embedded images they've already added to existing gallery albums.

So when I go to import to gallery, these images don't get selected.

This may be by design, so this may actually be a suggestions. But it would be nice if we could optionally select all images in a thread to import, even if they already exist in a different album.