Sorry to hear about Dozer's diagnosis. It sucks to be part of this club.
To paraphrase the Alzheimer's organization quote -- "If you've seen one person with dementia, you've seen one person with dementia" -- same with this !@#$% disease. Lots of commonalities, but plenty of diversity in how it presents, how animals react to the die-off, how long the die-off takes, and what pops up in the future.
My dog was diagnosed 3 years ago with 3-4 systems involved and was moderately sick. When we started meds, she showed NO signs of die-off. None. She just got better, although still has blasto in her eyes.
To me, the absolute worst part of this disease is there are no definitive answers about anything, everything's a "gray" area. At least that's been my experience. The vets couldn't tell me if Chick would survive, how sick she would get, if she'd get her sight back (she did and then lost it again), how quickly she could be cured -- or not.
So take a deep breath and try to minimize expectations, good or bad. Be hopeful and positive and stay away from what-ifs. With blasto, you'll drive yourself crazy if you try and predict the future. It' just a horrible disease with just enough answers to makes us pull our hair out.
I'm hoping Dozer gets through the die-off soon and makes a full recovery, read through this forum and you'll find those miracles. Hang in there and try to live in the moment with him. It'll help save your sanity as you play the waiting game.