The main reason for a DAM really is to have some trust that integration with the SW you love and have invested time to master (e.g. affinity photo) is given. You want to work within the look and feel of the SW you use for most stuff. IMHO a DAM can start out very basic and add features as requested. But it would keep you within the affinity universe, speeding up your workflows and reduce learning time for people working with/for you.
Why buy affinity if your DAM from another vendor already does much of the job? Many photographers don't really use Photoshop all that much and do most of their work with Lightroom. So why buy Affinity and invest learning time when you already spent much on LR or C1 etc? Yes, freaks and experts posting here may know the strengths of each product and master them all, but those will not be the lot paying for licences who makes investment worth while.
So my pledge to Serif: Please give us a simple, robust DAM to start with, that integrates well with Affinities products. Take aperture of even mac's photo app functionality as a start, but keep it open so we can migrate in- and out easily. Get our workflows into your world starting from managing the photos, and keep us within. I am so sure this will pay out for all of us.