I was thinking of some short-turn points that aren't listed on the schedule, that are done at the dispatcher's discretion.
M100:
129th Street (coming from the north)
5th Avenue (coming from the north)
M101:
161st Street (coming from the south)
Bx19:
Lenox Avenue (coming from the east)
M1/2/3/5:
42nd Street (coming from the north)
M5:
Chambers Street (coming from the north, or at least according to a video by a user here)
What I mean by that, is for example on the M101, there is not a single bus scheduled to short-turn at 161st Street from the south. But something like the M5 short-turning at 135th Street doesn't count because even if that particular run might not have been scheduled to end at 135th, it's still a short-turn that's listed on the schedule (there's runs that travel from South Ferry to 135th, and 178th to 135th).
What are some others you can think of?