The outside line is a function of the lockers I think, they have plenty of queue past the entrance if they choose to use it. With everything open there is 3 hours worth.
You are correct. If you're outside the gate to the forest, there's issues at the lockers.
And the clarify lingo - the "forest" is the switchback along the side of the building that's before you turn down the main path to the lockers. Beyond the lockers is the dungeons and then the gardens and the greenhouse. The forest touches the gardens and can technically be set up to use part of the gardens, but usually they stay using their intended space allotments (one being pre-lockers, one being post-lockers.)
When the queue extends into Hogsmeade it's because the lockers are overwhelmed. The operational goal is to have the "real queue" (post lockers) begin to form somewhere in or at Dungeons. This requires a LOT of work on the part of the TMs and rarely happens. A usual day has a lockers attendant (3rd party) and two Potter kids (Dungeons/Lockers position and Express) running everything down there. On a peak day it's at least 2 locker attendants, 1 student prefect with a locker key, 1 dungeons prefect directing guest, the two usual students, and then a castle prefect spieling to the approaching queue about locker requirements and to give items to one person in the party, and another up ahead in the line double checking for anyone who makes it past with a bag.
Some, but not all, of this could be solved with MORE SIGNS.
Control for FJ, which posts the wait time, actually watches the front gate, hogsmeade main drag, JP bridge, etc.. via camera and makes changes to the queue and staffing according to what's going on. Extended queue can go down the Hogsmeade path to the JP bridge and switchback there and also in the JP entry area if needed. But it can also expand into the backstage space between the gardens and the greenhouse. In theory all of the space past the lockers will be used before the chains out in hogsmeade and JP, but the lockers rarely allow that.
You can, and often will (especially with the morning rush), have the line down Hogsmeade and switching back on the JP bridge while the gardens are empty and the "real line" past the lockers doesnt form until the Greenhouse.
