...is a standard menu form in US restaurants where one has the choice from two or three selections for your entree and then from a dozen or so options you choose two or three vegetables.

That is the model for PD for us to consider. My own version has, in Column "A", inflammation with a garnish of hyper sensitivity to LPS (bacterial toxin) or an alterred stress response. From Column "B" you choose amongst mercury, rotenone, manganese, aluminum, stress again, more LPS, a selection of viruses, H pylori, etc.

You don't have to order all of these in order to be a Blue Plate Special but you do have to order the minimum combination - otherwise you are something other than a BPS. So, if you do indeed get a big helping of meningitis-induced inflammation and open your BBB for awhile, but you don't order any toxins with it, then you don't have a BPS.

Conversely, a surge of toxins and an intact BBB still no BPS. Ah, but if you are so unfortunate as to order both that day....

That is the "Many Hits" hypothesis. And now I'm hungry...