I have 5 family members using Synology Photos (on a 4-bay Synology NAS) and it’s a great solution for us.
I don’t see myself going back to a cloud-based solution - this one is easy for me and secure.
I’ve got SHR running on my storage, and daily offsite backup to another family member’s house (protects against house fire etc for loss of 20yr+ of photos and videos).
Once you offload from your phone, you can pare down the photos remaining on the phone to whatever you want to be left.
If you’re going to paint it, take the opportunity to sand the Z seam off before doing it