I didn't figure # 3 at Knott's would have much experience with snow, maybe an occasional pile of popcorn?
As I understand it the two pilot plows are operated with a lever from the cab. I don't believe these would be classified as flangers as they don't go down into the rail flangeway. You probably wouldn't want that anyway as any misalignment/ obstruction and you would probably rip the whole pilot right off
Here is a link to a Google book that describes the Priest Flanger which was used on RGS/ D&RGW locomotives that perhaps will add some further prototype information to this discussion.
Priest flanger description