I think it should be automatic, with a option, like a check box, or in the case of the remote access, just a variable set to Y for yes or N for no, because MOST of us, when we are trying to sale our reseller packages always say that their customers are theirs, and we will not try to take them, so if they leave, they should be cancelled too, but in case a reseller just walks away, that is what the checkbox or N would be for, so the customers don't lose all their data.
Then it should prompt us for which reseller to place them under, listing root too, incase we just take them over.
Seems like it would be simple. Seems anyways.