I spoke to Pat on the Sunday evening before we left Gatcombe. He said the main reason that there was no trackside camping was due to the roadway/track crossings that would be required. There was a very large trackside camping area for solo riders, but there was no vehicle access to it.
Pat said that roadway and track crossings would have required extra marshalling. He also said that the fence-line along the track that would need to be crossed was also interspersed with Zara Philip's training jumps. Under no circumstances could these be damaged. I don't otherwise think that there would have been an issue with riding where the camping took place.
There were understandable limitations with the venue and I can understand why, at least for a first visit, these had to be strictly adhered to.
Pat also said that he thought Gatcombe Park would be a one off, but apparently HRH was delighted with the event and so it looks likely that Mayhem will return next year.
I sincerely hope that there can be a return to trackside camping as it makes such a huge difference to the whole event.