So the hunt is truly on to see if we can find some cultivars that, like EMOs, sunfast, colorfast, etc., will not only hang on but be contented long-term with their sheltering awning of trees. Of the ones I listed, three stood out for not only a great blooming season and vibrant performance, but have thrived (so far) for three summers and two winters in the shadiest spot of all:
Dixie Land Band - performs basically the same as the one on my sun porch
Party Popper - very vigorous, but also grew and bloomed a bit bigger than its sun garden twin
All About Eve - most consistent and just kept blooming away
I always plant one fan in the sun, and one in the shade, so I can compare and note how they fare. The more evenly they perform, the better the long-term potential seems to be for the one in the shade.
I'll also mention Darker Shade which was just stunning in the shade and bloomed so well, though it had a little more access of an hour or two of direct sun each day. The other three are completely shaded by trees with limited indirect sunlight (zero-lot lines, 2-story walls on either side, and notched into a corner of the house under two very thick trees that never lose their leaves). I'll be interested in seeing if we can collectively come up with a few that really seem to break out of the mold and give daylily lovers a new facet to explore.