I'm not a huge fan of the idea. It seems like it'd become more of a hassle than what it is worth. I have been at the max and it is annoying but dumping prospects alleviates part of that problem.
I am not a fan of that. Just because someone trades all of thier picks and minorsaway, doesn't mean they should be able to trade thier minor league years also. Gives teams more money than the salary cap, allows other teams to stock pile minor leaguers. Why fix what works right now.
To me that would be like selling spots on the major league roster ... it just doesn't make sense. If you want to have more minor leaguers, then raise the total number of years for minors. I only see bad things from selling minor league years.