I’m realizing now that I’m not sure how upgrading a gang is intended to work.

I’m realizing now that I’m not sure how upgrading a gang is intended to work.  When I first read it I thought upgrading a gang could add a new gang type, or get an advantage or get rid of a disadvantage, or could raise the gang’s quality, but would only do once of those.  Now I’m reading it as, a new type, one of the advantage and disadvantage, and upping the quality.  What is it supposed to be?  It might help to make this more clear (I wouldn’t be surprised if the more complete draft already has it explained better in another part).  What have other people thought?  I wouldn’t be surprised if both interpretations are somewhat common.