The fascia is part of the JIN system as you can read also at Interview with master He Jing-han on Bagua quan post from 2011.
“We try to develop so called Jing and we call it the Jing system. It consists of muscles, tendons, ligaments and fascia. Thanks to this system we can connect each individual joints. When the tendons are short this connection is not possible. This means that we use muscles by stretching them.”
Lecture about fascia and its training, stretch the joint to train them and …
Watching a video and discussing it
About fascia, and why does internal style practice fascia?
There is quite a few material available on the internet, here are some examples, chosen just as personal preference
TCM meridians and fascia: what do they have to do with the internal arts?
THE SECRET OF FASCIA IN MARTIAL ARTS
Tai Chi, Fascia & Biotensegrity
Winding and Fascia Changes
This might be partly familiar from the classes as well
…. “Winding is a method by which we put a pressure on the body tissues via specialised stretching and rotation that will result in quantifiable change.
Placing the right demand on the tissue is extremely important as our body begins to adapt.”
How Tai Chi Targets Fascia and Connective Tissues
Tai Chi, Fascia and Whole-Body Movement
Just about Fascia, among many books maybe worth to see this one
Fascial Fitness by Robert Schleip (Author), Johanna Bayer (Author)
HeJingHan BaguaQuan, Baguazhang Teaching Taipei.
See more videos at Youtube playlists
some materials could be added from HeJingHan book:
Bagua Quan Foundation Training