It says in the video blurb that this is all footage from a single trip, which is fucking bananas not matter how you slice them.
As to massive handrails a lot of the biggest ones that have been done haven't even been down stairs so it gets hard to compare. Remember seeing one from Herman Stene last year or so which they had to film from two angles because they couldn't fit it into a single shot. The only thing that's limiting people now seems to be how steep it is.