From reading up on the rappel vs. lower dilemma, I often see references to "local etiquette". For example a related question mentions that:
Some exceptions to the "climber's choice" rule would be if the area's guidebook says otherwise, or if the local climbers all rappel ("do as the locals do" is always a good rule of thumb). In seldom-visited areas, I generally rappel.
But who is the "authority" on what the local standard is? I imagine that if I go up to climb outside of the most popular hours, there will only be 2-3 climbing groups nearby and there's no way to know if the people I'll see are a good representative of local rules or not. So what is the best place to figure this out, ideally before driving out?
E.g. if climbing in Exit 32/38 (Little Si) in Seattle, do you have to rappel or can you lower?