I didn't test, but I have two shared adress IP and two packages in my admin account. When I add new user, always user has default IP. Obviously I can change user assign IP but I'm looking for solution, where assign IP will work automatic accordin by package and I think that solution would be greate when you have few shared IP in admin/reseller account and you want to separate users.
For example Basic package has 500 users and Premium 100 users. When some user from Basic will be spamer and IP will be black list, Premium users don't have an issue with mail delivery.