Would it be correct that a Vectorscope effect on a 3D layer doesn't behave as though it's mapped onto that layer, rather it remains projected to the final 2D frame?
Also, if I've got a Vectorscope on a layer in a 3D scene, it seems to disable the ability to RAM preview? (I was trying to use this as a special effect, not as an analysis tool.)
I've partly answered my own question: I had it on a "Grade" layer so that was the problem with the 3D positioning. However, the RAM preview issue still stands - it won't run at all if there's a vectorscope effect in the scene (if I disable the visibility of that layer then RAM preview is sweet).