Seems to work fine for Locus Gear with their dome tent.
Indeed the Djedi looks good.
I wonder if the issue is truly rooted in fundamental mathematics and stretch, or if it is simply just an unforgiving application that is difficult to get right. I think it’s pretty clear that SD didn’t get it right with their UFO, but some of those other DCF tents look like they pitch pretty well. Even my first (and only) attempt a MYOG cuben dome turned out pretty nicely:

I suspect what is going on is that due to the lack of stretch with cuben you can only have a panel that curves in one dimension. So you can’t wrap a ball with cuben and do a nice job of it, but you could wrap a cylinder. This is largely true for any fabric, but with stretch you can cheat this a bit with other materials.
LG’s Djedi dome tent has very little (or no) curvature around the base. So the base is basically a rectangle (not a circle) and thus the panels only curve inwards (one dimension). So it works.
Getting back to the DCF Fly Creek, the panels mostly look like they work, but there looks to be a bit of two dimensional curvature. Particularly near where you pull out the two back corners. So I wouldn’t be surprised to have some hard to avoid wrinkles there. While wrinkles in the pitch are unsightly, they probably aren’t a large functional problem. Wrinkled but no sag cuben may be a better choice that nicely pitching but sag prone nylon.