This is a very timely thread!
I just came in from working on one of my seedling "beds" (in this case, two plastic storage containers filled with daylily seedlings in tree pots). I was finally getting around to triage.... throw those ones out, save these ones (either for a 2nd look, or because they still haven't bloomed), pot these four up larger (for another look and maybe some pollen dabbing).
Of the 14 or so total that I kept out of that group of seedlings (yes, small time pollen dabber here), only 1 or 2 were clearly dormant daylilies. One or two were almost certainly evergreen daylilies. The rest, I had to note as either "SEv -> Ev" or "SEv -> Dor".
For my garden, in my climate, I don't really care what the foliage trait is, so long as the foliage is disease resistant and otherwise good looking (no upright foliage). I do have a growing fondness
for blue-green foliage, though; the registered cultivars in my garden that have such foliage, also appear to have the healthiest foliage (though that could just be serendipity). And those are all dormant daylilies.