Yes, this PVP previously assigned, have used before.
Launch fare offer for Elite booking...reduced fare, and FCC OBC's.. The fare is refundable and can be adjusted for sales and promos as applicable. Sometimes PVP has found a regional fare special or even a casino rate that I may qualify for which TA has never mentioned to me. (Casino rate? Who knew?) There can be different fares under different codes at different times throughout the year. PVP has access to all, and emails me general notices when these are available and I can call and discuss my options. I still need to watch my bookings on Princess website for any changes in fares...price drops and flash sales and call PVP to apply. But I have always done that diligent monitoring even if booked with a TA. I do not just book and leave it all up to TA to monitor and notify me.
Transfer if a TA offers additional benefits? NP I have booked with Princess and had no difficulty transferring booking to TA for additional perks such as a lower group rate or additional OBC, specialty dining, etc. Nailed some super deals that way. I think now Princess limits the window of time permitted for transfer of booking to TA. It used to be right up to time of final payment, but now I think I saw something like transfer to TA only allowed within 60 days of booking.