My bluegrass guitar teacher is a firm believer your method , Julian. It is a group class and now the goal is to take a key and do the pentatonic for each chord up and down in that chord. And then do it over a song, simple ones at this point.
He calls these linear breaks and to me he makes them sound very good. I am working up to doing a scale (C chord) or double scale (G chord) in G C D A E chord’s. I think I am encroaching on his technique, but the pace of advancement is very slow and I have a ways to go. His belief is that you learn the scale, at the fastest speed you can do cleanly, to the point of not thinking about it and that as you discover embellishments you add to you bag of licks.
I am not a fan of what I call scale running to do a break. I like a Carter style that imposes a melody over the chords, But I have seen instances that sound really great so there must be something to it.
BTW thanx for posting those videos. I would like to know of more of them to study what others are doing.