It sort of all is?
It’s not a mass start, and you will not be allowed to enter a timed section immediately behind your mate – 30s gap between riders seems the norm.
It’s all chip timed not gated, so you beep a little tag on your wrist at the start and finish, and at the top and bottom of any timed stages. This means that so long as you don’t blow the entire time budget and find yourself still on the course 5.5 hours (I think) after starting, you can roll up to stages in your own sweet time and go as soon as anyone who was already waiting has gone rather than chasing transition times and minding potential penalities for missing your gate time…