Large hard area 6 months after Smart Lipo. What can I do next?

I am sure what you are describing is a result of deep bruising which is often worst in this area of the abdomen. At 6 months, there are no other treatments to do but wait another 6 months and be patient to see if it eventually resolves on its own (which it very well may).

Without showing before and after pictures we can’t really make an assessment on the outcome of your procedure.
The most typical reasons for patients having firmness long-term after liposuction is due to the surgery being done in an aggressive manner which removes most of the fat and leaves patient with increased scar tissue. If almost all the fat is removed then all that’s left is scar tissue which is firm and has no soft fat to blend with.
Unfortunately aggressive liposuction is permanent and irreversible.
I don’t believe massage or herbal supplements have any impact on final results after liposuction. The results of the procedure are entirely related to what happens during surgery and postoperative regiments do not change the outcome once the surgery is over.
Follow up with your provider or schedule proper in person second opinion consultations if needed.
Best,
Mats Hagstrom MD

Hi and welcome to our forum!
Without an examination, it is impossible to "guess" the nature of this large hard area. It may represent residual swelling, deposition of fibrous tissue, or a seroma. Radiographic studies may differentiate among them and be of value. If it represents swelling, it will abate with time.
Continue follow up care with your plastic surgeon as it may take 12-18 months to resolve.
Best wishes...