There are at least two ability skill tree talents that trigger markswoman abbilities. Namely “Arrow Traps” which triggers “Detonating Arrow” and “Dark Plumage” which triggers black arrows aka “Dark Quiver”.
So scince both abilities should be locked by choosing not the markswoman specilization, you cant spec into those and therefore can’t improve those triggered effect.
So my question is: am I missing something or are those interaction with the markswoman abbilty just trash?