I've gone 6ish times to HHN and I film every time I go and have not had this happened yet
I also do move, I do my best to never hold up the line. I've been going to HHN for over 10 years, its a congo line, always has been and always will be until they sell less tickets.
Fright fest has like 1/5 the guests HHN does, so they can have groups go into houses many times but HHN? It would be almost impossible without doubling lines.
I will say only going to Fright Fest once and HHN, Fright fest actors are just different. HHN do a great job but Six Flags many of the characters talk to YOU, so in a way fright fest can be scarier if you don't want to get singled out.