For only having PMR for one year, it sounds like you are doing pretty good with the tapering. You might find this discussion helpful as others have shared what helps them.
--- PMR Dosages and Managing Symptoms: https://connect.mayoclinic.org/discussion/pmr-dosages/

I use Multiprofen CC Plus. It contains amitriptoline, baclofen, ketoprofen, lidocaine, pregabalin. It’s a compounded cream, made in Canada, a prescription is required. m-line pharmacy.ca. Some days it works well, mild pain. I find if the pain is deep it’s not as effective.

I would have to disagree with the statement that Voltaren gel does not work on shoulders. I use it on my neck and shoulders and it helps a lot.

I feel like it’s worth a try, if you don’t mind paying for it? I’ve never heard it said before that it’s not effective for the shoulder. I have been told several times it works best when the source of the pain is closer to the surface of the skin—but that’s because with topicals, there’s a limit to the absorption of the anti-inflammatory. But then again it’s hard to know exactly where the pain is coming from and sometimes even an indirect approach can give relief.

For what it’s worth, I’ve also tried CBD cream and have found that to help; so had my dad with his PMR pain. My Neurology NP explained there are receptors in the skin for it, which could explain why some people might feel relief?

Hope the Voltaren helps though!