I am not sure I understand the issue, are you or are you not wanting to backup those memes? Because in the immich app you can select the folder to backup from, e.g. camera, and in the timeline on my phone in the immich app I only see my camera timeline plus backed up images, but not other folders on my phone.

If you mean they all get backed up from different folders into the same timeline, then yes, that’s a bit stupid. I have a situation like that and what I did was to make a separate account on my immich server just for art I find online I am collecting. Then I don’t upload through the app, although with switching account you maybe could, but instead move those images into that accounts external library. Then share the whole library of that account with my actual account. Then it appears in the shared tab. But I understand that might get too cumbersome.