There’s been quite a few threads about this kind of thing lately. At my CLF school, there were a few people who were pretty keen on sparring, and we did basically everything I saw in that “optimal” video, with the exception of the submission holds, albeit with 12 ounce gloves, as our sparring was more sanshou oriented.
My school was open for 6 days a week, with only 2 of those days being form days. On form days, we would warm up for 15 minutes (including going over basic forms), then work on the form we were learning for 15 minutes, then go into about 5 minutes of three star before working applications for the rest of the hour.
One of the days was a “bag day”, where we would warm up for 20 minutes (with light calisthenics - 120 pushups, jogging, crunches, squat jumps, etc) and then kick bags for the next 15 (low/high round, side primarily) and then work 3-7 punch combos for another 15 and then work some two man drills.
The other two days were only sparring. You warmed up on your own, then put on the gear and did offense defense for 5 minutes each, then medium continuous sparring full gear for the rest of the class, switching partners, and sometimes breaking out the mat to do takedowns and full contact sparring. Often we would focus on close range fighting, since that was most unnatural for us. Some days we would just warm up and just go right away, skipping the offense defense and focus exercises. I was not as good as my little brother, who could easily go for 45 minutes continuously fighting sifu (not winning obviously, but not tiring either), but I could also go full speed for 20 minutes and more - the conditioning from going to sparring classes regularly was very very good. To get an idea of the intensity of the full contact sparring, many of us were also regular weightlifters - I am about 145 pounds and lift over 225 pounds in most directions, my brother is 200 pounds and lifts about the same in every direction except straight up - so we could and did dizzy people, although most often it was ourselves (no weight divisions in class). Oh and sifu was also 145 pounds and could bench over 315, so he had dynamite in his hands too.
Admittedly, the sparring days were the most sparse - there have been times when only me or my brother showed up at all! But typically there was about 6 people in those classes compared to over 20 on form days. My sifu was much more interested in sanshou and fighting, being formerly a sanshou fighter himself. I guess he also got disappointed with the lack of people dedicating themselves to learning to fight and ended up closing the school last year. But the sparring classes were very good and very intense.
My point is, I have heard that one of the other schools near my sifu’s school is also similar in their class schedule - and I’m not sure the problem of kung fu schools lacking live partner training is that widespread. Maybe not every kung fu school is as intense, and part of the problem definitely is in the student interest, but I think most kung fu sifu’s would like to do live partner training and sparring, as evidenced by the many instructors on this board. It really is up to the students, though, I think. If students show interest, then you guys can teach it!