A plate solve when looking at Polaris is not a good ideea: the solver has a very hard time to distinguish between a 180° RA rotation and a 180° camera rotation. It might throw your scope completely out of sync. If you want to do the initial sync manually instead of the “slew to target” followed by the “center target” sequence, better slew the scope somewhere else first, using the motors.
Re. “just so SGP knows where it is pointing”: This is not necessary, as SGP does not keep track of where the mount is pointing. When SGP needs this information, it will either ask the mount where it thinks it is pointing or will start a plate solve as needed.