I think the jumping part would have to be the same (like releasing the same way you would in the hunter/jumper ring!). ;) They do look like they have lots of contact...but I agree with M2G- they are very experienced & are at a high level.
Anyway, I think it's great you'd like to start some XC! At my barn we have an XC course/field & it's very fun (I'm also a hunter jumper!).
It gets the horses used to being somewhere else rather than riding in an arena, since it's open. About trailering to another barn, I think that'd be pretty cool too. It's worth a try!