Thank you for all this info.
I'm not sure it's pertinent here, since your O2/rebound pattern is older than this and the D3 seems to have corrected any effects from lithium, but lithium is notorious for creating rebound attacks when its use is discontinued. Some medical literature suggests only prescribing it for chronic CH since the rebounds from getting off it are so bad (and the side effects in general are so typically noxious).
I also had a hard time understanding Batch's hyperventilation instructions, but what I think is correct is that there are a series of very short, very deep inhale/exhale "cycles," each lasting just a few seconds, and that you do ten of those cycles with room air, in a total of about 30 seconds, before you start on the O2. I'm going to paste below what I think is his most recent writing about this. You might not have seen his "redneck reservoir bag" approach; these instructions are part of it (link to it is below).
Yes, it could be that staying on the O2 longer after an abort will hold off some subsequent hits. I think "5-10 minutes" is the standard advice.
This is the doggone thing that makes anecdotal evidence so challenging. My daughter (the person in my family with CH) never took any CH meds except, for a short while, gabapentin, for the first ten years she had CH. She didn't even have oxygen. But her cycles got longer and worse, pretty much year after year.
Nice story about Ben Khan. I wonder how many people with CH are indebted to someone who reached out a hand to them. I know that as a family member, the kindness that Bob Wold extended to me about 8 years ago will never be forgotten (and still brings some tears of gratitude to my eyes). Somebody here might be in touch with Mr. Khan.
Here's Batch on hyperventilating when using the "red neck" method. You can see the whole file, with details about using the redneck bag, here: https://clusterbusters.org/forums/topic/4919-batchs-hyperventilation-red-neck-bag/ When you've hyperventilated for 30 seconds (ten complete cycles) per the procedures below... [These are the procedures] The exhale part of this procedure is important. Exhale rapidly until it feels like your lungs are empty... They're not. At this point you do the abdominal crunch and hold the chest squeeze until your exhaled breath makes a wheezing sound for a second then throw your shoulders back and inhale as deeply as possible then repeat the exhalation with a crunch in one fluid motion. Ten of these complete cycles in 30 seconds should start to push your body into respiratory alkalosis... (Remember the movie "The Andromeda Strain") On the tenth exhalation, hold the squeeze/crunch until your breath makes a wheezing sound for at least 3 seconds... or until you stop wheezing... This will squeeze out another half to full liter of exhaled breath that's highest in CO2.
You'll know you're doing this procedure correctly when you feel a slight tingling or prickling on your face, lips, hands, lower legs and feet. This is called paresthesia.