CLF-particularly in BSCLF, the movements are very large, with full stretching of the joints. (a;though, this is also depending on how the individual plays the form., so it is not limited to BSCLF.)This maintains flexibility, and opens up the energy pathways.
i can tell you he wasn't taught by US to move that way. he is more of a chan family stylist.....they have shorter hands than Hung Sing and Buk Sing in my opinion.

Does his student train this way?
students tend to look like their teacher. by my sisooks ive been told they can see in my hands that i am my sifu's student. my senior students have seen my more jr ones develop my hands......so it may be safe to conclude that students tend to resemble their teachers.