Unfortunately, with MSP you cannot have a single payee number connected to more than one service at a time. This number is what they use to determine where to send payment for claims submitted and the remittances.
Getting an additional payee number will not change anything else for you. You do not even have to remember the number. Your practitioner number will stay the way it is and you will just have a second 'payee number' to tell MSP where to send the money for the claims we submit for you.
If you decide to stop using Dr. Bill, that number will simply sit inactive until you decide to connect it elsewhere if needed.