First of all I love this!!! If you ever have any more of these type of theories that you want to process let me know!!
I think what you said, “less likely” is key. The reason I say that is because POTS symptoms can be on a continuum, as in sometimes it flares worse than other times. Also pointing out that the key word is “effectively” so it would be logical to say POTS could cause lower or higher constructing from triggers that would cause abnormal reaction to the stimulation. We have a problem with over/under constricting and dilating in areas that shouldn’t be then it could also go the other way that some patients are more likely to get brain freezes and not get brain freezes versus others with a well regulated nervous system. So my question is does they type of POTS correlate with the outcome?
Just looked up some more info so I could have little more logical reply… brain freeze is more likely in ppl with migraines and is caused by quickly dilating blood vessels to increase the temp in the area. It’s also linked to trigeminal nerve sensitivity, which effects the cerebral blood flow velocity (also effected by sympathetic and parasympathetic). CBFv is compromised in 50% POTS patients. (This deep dive is incomplete and have to get back to work now so I apologize for that but hopefully helpful to get more wheels turning and I will get back to looking into this later).
From personal experience, I drink a smoothie nearly every day and like it to be more of an icee consistency.
Sometimes I notice brain freezes by just a tiny sip and am like wow really that was barely anything and then other days no brain freeze. Also, my blood vessels dilate more than constrict and at times when they shouldn’t be. So for me, that makes more sense why I would get more brain freezes because it’s like my body is just waiting for the smallest stimuli to over react to and dilate, which is quite annoying.