There is an abundance of 'trial and error' when treating any medical condition. No two people are the same so what works for one may not work for someone else.

I don't know for sure if I'm "PMR free" or not. I have been "prednisone free" for almost three years. I still take the biologic and I'm "relatively pain free" and "PMR condition free" until the biologic is stopped. According to my rheumatologist, PMR goes into remission and the pain is relieved but my PMR condition still exists. He thinks my immune system has been attacking me for a very long time. A characteristic of the adaptive immune system is to "remember" what it attacks. My rheumatologist doesn't think my immune system will "forget" anytime soon what it has been attacking for many years.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4067599/
I wish someone would debunk this idea for me.

Prednisone never helped my overall condition but it did quickly relieve much of the pain. That is how Prednisone is deceptive because it doesn't change the overall course of the condition if you need to wait for PMR to "burn itself out."

My rheumatologist is reluctant to stop the biologic again because my condition worsens. I wouldn't say I have PMR relapses but my condition deteriorates and I need to go back on prednisone again temporarily. When the biologic is restarted it takes time to work. There isn't the immediate gratification of pain relief like prednisone provides which is deceiving in my opinion. People are not well if they need to take prednisone every day! Symptomatic relief and waiting for the PMR condition to burn itself out is not good enough. The waiting and the long term side effects from prednisone is a recipe for disaster in my opinion.

The biologic takes a few weeks to work. I currently do a monthly infusion which is nice because I don't worry anymore about how much prednisone to take each and every day. That is what "prednisone free' means to me. I don't want to take long term prednisone again but I will if it is necessary for a short period of time. My slow motion relapses don't happen instantly like when my prednisone dose got too low which often happened overnight. I don't feel like the biologic fails when it is stopped. When my condition deteriorates and the pain becomes more than I can tolerate, prednisone is restarted. I only take 15-20 mg of prednisone for a short period of time. Fortunately my condition dramatically improves again when the biologic is restarted. I then taper off prednisone again in a couple of weeks. This was a 'trial and error' approach to see if the biologic could be stopped. However, one interruption was a supply chain problem during Covid when the biologic was not available. The biologic can easily be stopped unlike prednisone when people become dependent on it.
https://www.medicinenet.com/steroid_withdrawal/article.htm
My rheumatologist had two goals when he sought approval for the biologic. The way the request was was worded --- "all other alternatives failed" (notably methotrexate and leflunomide and a few other steroid sparing medications) AND "inability to taper off prednisone." My rheumaologist's first goal was PMR remission and the second goal was to get me off prednisone.