My best guess is that the dramatic circuits themselves, at least at the Signpost & PSR Variation level, are specific to the throughlines that they're in. Since the storyform and PSR do place the elements of those circuits in individual throughlines. BUT the "story content" or illustrations of each item in the circuit can exist in other throughlines, and be seen from that different perspective.
Example 1: IC Signpost 1 of
Memories has the IC doing stuff that impacts others in the area of memories, including using a spell to draw out someone else's memories. Some of the stuff he does, including the spell-casting, could also be seen as problematic
Doing which is OS Signpost 1.
Example 2: Act 1 MC Througlhine has
Suspicion as one of its PSR Variations. Act 1 OS Throughline has
Attitude as one of its PSR Variations. Both might be related to some of the characters suspecting that the MC is a witch tainted by the devil, their suspicions fueled by their attitudes towards those born with magical abilities. (Suspicion and Attitude may or may not have the same PRCO assignments in their circuits.)
Of course when it comes to the scene level, as shown in Jim's Narrative First articles, I think the individual scene events can exist in multiple throughlines -- and in the best scenes they often will. (At least for structural scenes; I'm not sure if storytelling scenes are part of throughlines.)