Lower lot usually opens one hour after the park opens.
Here today and HPFJ opened for EE at 8:30 and Lower Lot opened at 9. Huge bottleneck on escalators. I would recommend stairs. We didn’t get to line until 9:10 (and we were part of rope drop pack) and off ride by 10:10. They had some technical issues and had to unload some boats.
Ride was more fun and more wet than I expected. Scared the crap out of my 7 year old though.