Could you please add a DAM to Affinity Photo? Or at least develop a program similar to Lightroom or Aperture?
If your looking for ideas please look at Apertures filing system. I have found it to be the most robust filing system as far as flexibility for storing images and sorting images. There are many neat features on it and I found it a lot more user friendly than Lightroom. It's editing capabilities are outdated, but it's DAM features are second to none.
Sincerely
JT