How are patients living with both MS and other autoimmune diseases managing symptoms, medications and their medical team?

I've had MS for 30 years, and psoriatic arthritis for 18 years. It is frustrating managing 1 autoimmune disease, let alone two. medication management is complicated because I can't take 2 biological medications simultaneously. I take a lot of medications, all of which have side effects. It is important that my neurologist and rheumatologist communicate with each other regarding treatment options. I think there is probably a large amount of people with similar situations. Is anyone studying people with MS and other commordidities?