It has been suggested to add custom section to the programs, besides the existing "Warmup", "Workout" and "Cooldown". These custom sections could be for example: “straight arm strength”, “bent arm strength”, “l-sit work”, "skill work", “athleticism”, etc.
The Warmup and Cooldown are much more than section names: they have special logic and algorithms linked to them for program generation and automatic suggestions, so adding custom sections would complicate things a lot and create new issues.
It would be easier to name Supersets, but then the section naming would not be availble unless the exercises happen to be in a superset.