I don’t know the JFS series, actually never heard of it. I would like to comment on the Pawanmuktasana series 1, 2 & 3.
P-asana 1 is especially useful for people with rheumatism, arthtitis, high blood pressure or other illnesses where the more vigorous asanas are not recommended. I personally do this one with a lady in my class who suffers from very high blood pressure and she always tells me that se feels so much better after a class. My own mother suffers from arthritis and I have taught her these asnas to alleviate her pain, with much success. Depending on the student, awareness can be in the physical body, the breathing or in the movement of prana in the body.
P-asana 2 series concern itself more with strenghtenig the digestive system and illnesses associated with the disgestive system such as constipation, excessive wind, acidity, diabetes, lack of apetite as well as varicose veins. I like to add this series to my own classes, especially beginners, as it strenghten the tummy muscles, which helps to build core strenght.
P-asana 3 series is the shakti bandha asanas and concerned itself with improving the energy flow in the body. It also helps to break neuro-muscular knots in the body, but especially in the hip/pelvic area where energy tend to stagnate. I recommend this series for people with a stiff back, ladies with extreme mentrual problems and as general toner for the pelvic and hip muscles.
Hope this helps to shed light on the Pawanmuktasana series.