In the video, Coach Sommer says to perform each stretch series (TB, FS, MS) once per week. Otherwise, you'll only make half the progress because you're too sore. Can you add any additional insight here? I'm the type of person that likes to understand how things work. Maybe some additional information on the time it takes for tendons to adapt would be helpful.
Another thing that is confusing is that the recommended default workout schedule by Coach Sommer recommends doing the stretch series twice per week. If I'm a 31-year-old male who stretched multiple times per week before starting the GB series, is it safe/beneficial to do the individual stretch series up to twice per week (in other words, with at least 72 hours of rest in between the same stretch series)?