I am currently studying Sun style tai ji, also. The manual claims that it is Sun Lun Tang's mixture of his skills from Bagua, Xing I and Tai Ji training. There is also a video of his daughter performing the form. I'll see if I can find it...

https://youtu.be/bOU402zqRLE?si=_fZ2Ct7HmRSzS3SC

@Luke Ouellette I somehow think that studying, long distance, is better. It gives you time to internalize because you are not getting anything new until the next in person session. It is certainly slower, but perhaps, more advanced?

From the Kung Fu Cannon in Tim's Xing I Book: "For those practicing martial arts, 80% of time is spent in solo practice, 20% of time is spent with others. Therefore it is said, “The time strengthening the body is long, the time defeating opponents is short.”

Thanks