MMI after 3 years, no health improvement. Settlement?

Hi everyone! I'm looking for advice as we are completely stuck.

My husband had a back injury at work and had WC case open. It took a long time (2 years) to have surgery approved and after it was done it did not help. Now a year after surgery we got MMI verdict with work restrictions, and that WC will no longer pay the weekly benefits. They are calculating the settlement offer now so we don't have details yet but we are not sure if we should contact the attorney.

We are questioning why the single doctor has the power to justify MMI (the surgeon who did the back surgery suggested that another type of surgery might help with pain, however, this independent physician who did the last evaluation said he didn't believe it would benefit, no further explanation given). Is there a way to question the evaluation?

Also, in case we hire an attorney but they are not able to change the offer, will we be required to pay the percentage of the original offer? This sounds quite risky.

Thank you for any advice!