2 years post biopolymer removal and butt is still hard. Can I have a fat transfer to achieve a fuller and softer result?

Thank you for your query. The hardness in your tissues after “all’ the polymer has been removed is most likely from scar tissue. Fat injections are probably the best method available to both enhance the volume and to restore the softness of the tissues. I would recommend multiple sessions of small amounts of autologous fat in the scarred area as the blood supply here may be limited. Please find an experienced board certified Plastic surgeon who can examine you and help you with all your concerns. All the best!

The fact that your buttock is “rock hard“, means there is a severe amount of residual scar tissue. Unfortunately, this is the norm following injections of fillers, such as biopolymers, PMMA and silicone. Because your buttock has so much scar tissue, it will not except fat transfer BBL. In fact, it will be a near 100% failure. Typically in this situation, the only relatively safe, reliable, predictable, an permanent option is to reconstruct the buttock with implants. Please note, an extremely few number of board-certified plastic surgeons specialize in buttock implants so you may have to travel far and away from home to seek consultation with such an individual. Glad to help.

Yes but need to see in person or at least do a virtual consult with... to see if you have any donor fat to use. Fees from $6,000++. Understand it may need a few surgery rounds to achieve the "soft" results.

Each plastic surgeon will have the round view on the appropriateness of doing a BBL after removal of various filler substances. Likewise, each individual persons candidacy for the procedure regardless of medical history varies quite a bit as well.
There is no yes or no answer to your question. I suggest scheduling multiple in person, consultations with local, board-certified plastic surgeons, who have extensive experience with a BBL procedure.
Best,
Mats Hagstrom, MD