It's entirely ad hoc per location at Telsa SCs in my experience, even as every Tesla using nav gets notified to leave as soon as they have enough for next leg of trip.

Usually queues are obvious where it's 1 way in/out of a charger block. I've found it's up to the first in queue to establish and 'defend' the queue though. Many times folks charging know and nudge / wave / flash lights at the actual next in queue while slow rolling out for them to get in.

Very common for those queues to be obviously double park or line up idling if there's enough room but again depends. The worst locations are where there's back to back rows and both row ends have entrance/exit. Common at Target or other SCs in very large but not long lots. Where, I've seen a queue form on both ends.