Backup Nextcloud without Data, or use existing borgbackup repo

Hello!

Is there a way to exclude some data folders from the AIO backup option? Or to add the Nextcloud backup to an existing borgbackup repo?

The situation is the following:
I run Nextcloud AIO on a VM, and i mounted some folder (like Pictures, Documents, Music, etc.) as SMB mounts directly to the VM inside the ncdata file structure.
I do this because other apps on other VMs also need access to those files.

I have modified the docker systemd file to start only after all those folders have been mounted. This works perfectly for over a year now, and i don’t have the limitations of mounting a SMB share over Nextcloud.

I already have borgbackup creating backups of all those folders, so I would like to avoid duplicating ~ 600GB of backups.

So, can I somehow exclude those folders from backups?
Or alternatively, can i backup everything to my existing borg repo with an existing repo key and key file?