Max length sets a limit for how many smaller bone segments can be merged. It doesn't subdivide existing segments. Same goes for max angle. This is noted in the docs.
However, I can understand why this may not seem fully intuitive at first glance. I will make a note to potentially allow the setting to also subdivide existing bones.
However, I can understand why this may not seem fully intuitive at first glance. I will make a note to potentially allow the setting to also subdivide existing bones.