I am planning on bringing in a second major league to my
dynasty, but I am strongly considering starting it as an unaffiliated AAA minor league to ramp it up for a few years, before recasting it as a major league (maintaining its inferiority) in Game Setup/Names & Affiliations when the season comes. I want to do this to implement a financial system, start generating pictures of players (which exists only at the Major League level), and other similar things applying only to the major leagues in my world.
My question is, has anyone else done this, and if so, what has been the implication to historical record-keeping, or more to the point, whether it causes the game to behave in different and unexpected ways?