I don't, but I've been at it almost 50 years, in the first ten years roll cast was 95% of all my fishing. There are a few ways to get line out there, but I'm guessing the novice doesn't know them. I also do it from the bank as often as not and very rarely back in the same direction of the "pick up", almost every cast is a change of direction. 40' should not be anyone's limit in roll casting either, if measured from feet to fly.Roll cast it out, bit by bit
My point is that a beginner not knowing how to roll cast, won't know how to "roll cast it out, bit by bit". I've watched a couple dozen of the roll cast and spey videos made by various actors and so far they have all assumed that the viewer already knew how to roll cast. I'd also bet that a video made form the casters line hand side would be more instructive than one made from almost any other position because it would more nearly represent the caster's perspective, but it may be just me that has trouble inverting and translating other views- I'm not at all video oriented.
I've never seen "good roll casting video", I have seen videos by good, very good and excellent roll casters and I'm sure that someone can pick up bits of technique from all of them. Personally I could learn more from a line drawing and stick figures.