Endurance Onslaught 6.0
youtube run is basically just following instructions, if beginners do something else they'd just fuck up balance.
relax run gives you generally more freedom, but imo not really since i just hold most of the joints anyway.
custom run is just a more "stylish" opener for a run, sort of.
Oh god, not this again.

Youtube run: Beginners can only take a few steps, often they lose balance doing anything else.

Relax run: Looks fucking horrible, you tend to lose balance fairly easily because your don't hold chest/lumbar

Custom run: The opener doesn't really matter, some of us use the Youtube run opener to start, what's custom is our arm style, how we use our pecs, the way we use our legs, ankles, we think more about what we do. Many of us take a good couple of months before we find our true run that looks good and that's fun for us to do.
You shouldn't worry about being held or relaxed, just do whatever works in your current situation.