The problem with these ban extensions is that it's only going to make players evade even more, all they care about is getting back to playing as soon as they can. That's what ban evasion is. Ban extensions should be saved for the more malicious players that hack, xray, or harass other players. Not the ones that did something stupid and bypassed the system to play their game.
You can't stop players from using alts to evade. It's not going to happen.