How busy were the lines in general when you went?
I was there for that flight a couple of weeks before xmas. As a non-status holder anywhere, I paid for a glass of champers online for the No1 lounge to guarantee entry with my Priority Pass card. That gives you access to the Premium Gatwick line also.
However when I arrived, I was able to walk up to the first ordinary security desk and start going straight through! It would have taken longer to walk over to the Premium Gatwick section!!