There isn't a single answer to that. The standard answer is that you return to the last effective dose and stay there till pain resolves and things stabilise. But it depends on the individual and their doctor. Some people take a few mg more for a few days before dropping to the last effective dose and staying there for a bit before resuming the reductions.

I've had only one flare last year at 6.5mg/6mg, so my flare management experience is limited. At the time, I waited on 6mg to see if the new pain would resolve but it got slowly worse over a month or so. reaching 5-6/10 before I knew it was a flare. Doctor said to go to 15mg for 5 days to resolve the pain, then drop back to a dose just above the flare dose. In my case, the pain was not improved at all after 5 days on 15mg, so I only reduced by a couple of mg. There is a window of fast reductions of 2 weeks (3wks tops) after a big rise in dose, after which only slow reductions can be made again. It took a month for my pain to go away, so the opportunity for a fast reduction was gone and I had to proceed with the original slow taper from 12.5mg.

So it can depend if you are a quick responder to prednisone (I am not), or if you have to be more patient. There's no set rule - everyone is different. It would be good if others could give you their experiences too.