This is another answer I believe to be incorrect or misleading.
Is off-season development distinct from in-season development? That is, if a player is promoted late season and gets a promotion bump, would that bump have been received during the off-season anyway? (pajammies - All-Star - 2:50 PM)
Distinct but related. If he has a very late season bump, it most likely means his offseason bump will not be as great.
Off-season development seems limited to physical traits while in-season development is learned skills. The promotion bump never increases a physical trait. Therefore, off-season/promotion development are not related.