Hi Linc, as you've now given up biologics, how about looking in a completely different direction for a while? Most of the meds that modulate AS seem to work by suppressing immunity, and maybe the way to go right now is to see if you can instead repair and build up your misfiring immune system, rather than looking for an alternative to block it. Also NSAIDs affect the gut, which is where most of your immunity resides, so they too have a negative impact on immunity.
How about looking for a doctor of integrative and functional medicine? This is a qualified doctor who has studied further and focuses more on getting to the root cause of illness rather than just treating symptoms. They tend to have one foot firmly placed in the world of medicine, and the other in alternative treatments. I'm guessing that most of them will have some experience in treating autoimmunity, though not necessarily AS, and you might even be able to find one that specialises in cancer. The one I visited knew plenty about diet, though not the AS diet unfortunately, but she was nevertheless able to give me some useful tests and excellent pointers for getting my health back. She acknowledged that there were things I had researched about my disease that she didn't know, so she wasn't prescriptive, but we worked together as a team. Integrative refers to the fact that they work together with other specialists in order to help you, so they might refer you to other likeminded practitioners.
Not necessarily a perfect solution, but it might be worth asking around to find a good one and having at least one consultation, and see if this is a line of action that appeals to you.
Good luck with your recovery, Jane