I think there should be some sort of buff, besides learning speed, for not severely exceeding Brain Capacity. Perhaps increased iMG accumulation or an additional quoin multiplier as a reward for not having a brain clogged with excess skills. It makes sense for Brain Capacity to matter beyond the short periods of time when new skills become available. The 'about Brain Capacity' pop-up on the Skills page describes an unstressed brain as 'a healthy brain' which implies that a stressed brain is unhealthy. We use our brains for more than just learning, so a glitch with a healthy brain should benefit more than just while learning.
What do others think?