Drew, It is very distressing to see what you have gone through. Your experience is an extreme outlier to all of the PCS sufferers I have ever known.

While I don't deny your experience, I don't believe anybody should be taking the extreme steps you do without first seriously considering any and all other remedies.

The practical value of the helmet systems you note is minimal at anything but very low level impacts. Reducing a 10 G impact to an 8 G impact may be noticeable but reducing a 50 G impact to a 45 G impact is not going to make much of a difference.

Walking down steps can generate 4 G vertical impacts. Those helmets do not help with that.