Welcome @mountainbikergirl, That's a good question but I'm not sure there is a clear answer. I do know that you can have PMR and also have normal SED and CRP levels.

"Can you have polymyalgia with a normal ESR and CRP?
The diagnosis of PMR is possible, even if ESR and CRP have not increased. US and 18-FDG PET/CT evaluations might increase diagnostic rates of ESR and CRP negative PMR. A rigorous diagnostic work-up and a long follow-up (one year, as minimum) are mandatory to avoid mistakes."
--- Polymyalgia Rheumatica (PMR) with Normal Values of Both Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) Concentration at the Time of Diagnosis in a Centenarian Man: A Case Report: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6313638/.

I do think that tapering off of prednisone slowly is key to remission. My first time took 3 and half years, second time took 1 and half years to taper off. What helped me the second time around was making a few lifestyle changes, eating healthier, less sugar and inflammatory foods along with a little more exercise. There is another discussion which might be helpful:
--- PMR Diet: Foods to eat and avoid: https://connect.mayoclinic.org/discussion/diet-and-pmr/.

Does your husband keep a daily log to track his level of pain and dose of prednisone?