The courtyard will almost always have at least a few blackshirts present, pretty much any hour after noon.
The crowd will grow as the evening wears on, fluctuate based on who's playing and their popularity, and will spike sharply after the headliner finishes, but there will always be a few folks who show up before then.
Some people aren't marathoners and don't see every band, hence the courtyard tends to have a number of blackshirts all night long. But pretty much after the last band is done, people walk the block down the street and the party goes into high gear.
I stick around for a few minutes, talk to my friends, maybe have a beer and then go to bed. I'm not a night owl by any stretch of the imagination!
I would think that it would be a good idea to patronize the host who allows these gatherings to occur. So, IMHO it would be in everyone's best interests to try to buy stuff at the hotel bar. However, I know there are special concoctions that veterans have brought that make the rounds....
Clean.I make the nightly call around 2-3AM after asking the Front desk for trash bags for a full round of cleanup and we normally pick about 2 huge bags of shit out of the bushes from back to street, and it's gross. While I don't expect it to change, I DO hope that more than the typical 10 people chip in to help this year.