Yes it is possible, however not exactly a supported Avaya method for SM and SBC.
SM the user will have issues running some commands unless they are in all the correct groups, some commands are only tied to the cust account as I remember.
In SBC you will have similiar issues. In SMGR you can do this through the GUI, and will need to allow the user administrative and CLI permissions. You will also need root access to SM and SMGR to do this. If installed by a vendor most likely you will not have root since Avaya requires a waiver to enable root on most devices now.