It would be a cool bell/whistle if players with no-trades could sometimes be bought out at the time of trade initiation, based on things like the record of the teams, the player's patience, age and how long he'd been with the franchise, etc. When you submitted the trade, you would get back one of a few possible messages saying things like, "I grew up an Ottawa Chiropractors fan, I'll never go to the Scranton Apollos," or "I'm willing to go to the Charleston Charge, but only if you give me $3M right now," or "Hey, I've always wanted to be a St. Louis Superstition, I'll waive my NTC." Then, if you got the middle message and had the $3M available in payroll, you could complete the trade.
This isn't higher than about 30th on my list of things I'd like to see them do with HBD, but it would be cool.