The majority of patients are extremely happy after their Brazilian Butt Lift, however occasionally patient want more augmentation than fat alone can accomplish. The benefit of the Brazilian Butt Lift prior to augmentation is that the persona has already had some liposculpting to improve their overall figure. Also the fat that has been transferred is used as a buffer to soften the implant in feel and appearance.
I would make sure that you at least two or three months have gone by prior to the second surgery with implants to allow time for the swelling to go down and settle. Once a patient has recovered from their Brazilian Butt Lift they can undergo a butt augmentation with implants with out any increased risk. They should actually have a phenomenal result!
Please discuss this with your board certified plastic surgeon.