So i'm of two minds about this, yes show up to town, no one is stopping you. But if you show up on trail runs either go in the morning early or later in the day. We had a few situations where people not part of FJ Summit, but were crashing FJ Summit either slowed our group down or tried to push past ours.
Keep in mind FJS has to spend a lot of time and money to get the permits for these runs, and organization, and if you go up there do not impact the schedules or enjoyment of people who fought to get in to the registration, paid a ton of money, and time, to be out there.
If I can't get in next year I'll crash, but be very respectful for the people who for them this may be their ONLY major vacation all year round. We got stuck behind 4 FJs who were crashing the event, and frankly didn't respect the trail schedules or consider that they were affecting people who were lucky to be there.
Basically, if you crash, don't be a dick about it.