I have no useful advice to give you on this matter. Febuxostat is just another way to do ULT. We can talk side effects, pill-cutting and stuff but it should have the same effect as allopurinol on your inflammation.
What I was trying to say is that if you’re confident ULT is what you need to do, what’s the point in trying to determine ahead of time what ULT would and wouldn’t solve? You’ll find out anyway.
I also assume you’d get a clearer pricture of the damage done by uric acid once it’s (mostly) gone than in the middle of the process (even if there was a point in having pre-ULT imaging, it’s too late for that now that you’ve spent quite a while under 400 umol/l).
Maybe I’m missing something.
About predicting damage, it seems we know one thing: the longer you’ve had untreated gout, the more damage there will be and the harder it will be to stop the damage from getting worse even with ULT. The relationship is going to hold regardless of exercise. Perhaps weight-bearing exercise could increase the amount of damage but I think that’s a separate issue from the matter of how you should behave during attacks.
About your assumption, the first times I got really serious attack, weight-bearing exercise involving the affected joint had disastrous effects. I very much doubt the problem was bone erosion or anything of the sort since no doctor noticed anything out of the ordinary, even on the MRI I had done back in the day. Granted, I saw a bunch of clueless doctors but that kind of damage can’t be easy to miss, right?