I use the Profile Dun pattern on the Baetis Rhodani and Ephmemerella Ignita, and on this fly. I love the way the wing profile force the body to sink into the film, creating a crystal clear profile of the Marginata. I like to tie the fly with a fuzzy thorax from Squirrel in order to suggest legs. Combined with the badger tails the result is an imitation with lots of buggy features.
The alternative Marginata (se here) has wings from Deer Hair. Those create a robust fly maybe best suited for windy days. When there is a light breeze, the CdC wing sway delicately with the wind. Maybe a trigger – maybe not.
The No Hackle based patterns is very well suited for this type of may fly. The idea is old, but made popular Swisher and Richards with their flies with Mallard wings. In recent years those delicate patterns have been replaced by CdC or Deer Hair wings, basically doing the same job but the flies being more durable.