You mention that steroids are doing a number on your bones ... back in the mid 80s, after a couple of years of relatively high dose prednisone, I was dx'd with avascular necrosis in my knees. Only a matter of time until I needed them scoped to clean them out.
Fast forward to 2009 and I had bilateral replacement at 46 yrs old. And that was after back surgery (because I walked like John Wayne for years). And elbow surgery.
Now hindsight is unfair, and there is no definitive proof that it was the prednisone, but I would have pulled the trigger earlier than I did and not subjected my body to the cocktail of medications that I did.
My 32 year ride has not been perfect but the years I lived with active UC were far, far more challenging -- emotionally & physically -- than the last 3 decades.
Last point and certainly an oversimplification, but after being on this site for years and talking to many UC/pouch folks ... my totally unscientific belief is that either you'll respond fairly early to meds or you won't. Folks will disagree but that search for the panacea begins to preclude 'rational' decision-making imo ... how many enemas? How many different meds? How many diets?
Today my joints are good ... I can climb and bike again ... keep the big picture in mind ... it's your life.