Stage Presence comes from Dancing Star X Snapshot. In turn, Dancing Star comes from Queen's Circle X Starring and Snapshot comes from Bold Vision X Next Millennium. Starring and Next Millennium would pretty typically be described as amoenas. Queen's Circle and Bold Vision would pretty typically be described as representing the Emma Cook pattern. Not surprisingly, Stage Presence is sort of intermediate between a classical amoena and a classical Emma Cook, so what you call it becomes somewhat subjective.
Gypsy Lord is similar in that it doesn't have any plicata heritage and could be described as an amoena or an Emma Cook depending on where you draw the line between the two patterns. As I said before, the Emma Cook pattern was derived from amoena breeding (and iris of both patterns are commonly crossed with each other) so it shouldn't be surprising that the line between them is pretty fuzzy.
I was always told that you shouldn't cross plicatas with regular (for lack of a better word) irises, but I see more and more showing up in the registry that do involve plicatas crossed to other types. For example, Alpine Harmony has a plicata (a sibling to Charleston) in its ancestry, not that you could tell by looking at it:
