I agree, but it's not as simple as taking an immunosuppressant. I've tried several that had no effect on my symptoms. It might be necessary to suppress one cytokine and support another. Maybe it's necessary to do both of those things and modify the HPA axis in a particular way.
I was able to trigger temporary remissions in the first few years, so it isn't impossible to do it. I expect it would take more effort to trigger remission now. It might take several drugs, supplements, and whatever else to 'set the foundation' for something else to trigger remission.
Play some role in maintaining the immune system dysfunction, if that makes sense. Causing to some degree a self sustaining cycle. Also, as you say, the low grade brain inflammation (HPA axis etc.) could also be causing dysfunctions in the body, helping to perpetuate them.