iPhone users using iCloud and Shared Libraries with a family member: When backing up using Synology Photos, how do you manage duplicates on the NAS that come from photos/videos in those Shared Libraries?

I’m currently backing up my own iPhone to my Synology NAS using Photos and it’s great! However, I noticed that it’s also backing up anything in the iCloud Shared Library where my wife and I share items with each other.

I want to get her backing up to the NAS as well, but I’m assuming that her iPhone will ALSO back up all those same items in the Shared Library and we’re going to end up wasting a lot of disk space with duplicates. Normally Photos or DSM might catch the dupes, but since they’ll be in different Homes folders I think they’re going to slip under the radar.

Does anyone have any solutions or best practices about how to manage this issue, short of just not using Shared Library on our phones (which would suck b/c I quite like it otherwise)?