Apologies if the meaning was unclear, but what it's meant to convey that I resigned ALL of my dozen-or-so positions from the org simultaneously.

For what is worth I understood your meaning immediately by applying the "most generous interpretation" principle.

Might I suggest phrasing it exactly like that then? “I resigned all 12 positions I held at Apache because X” is a lot clearer to me.

1/ because I don’t remember exactly how many, 2/ because the record keeping at Apache was so haphazard at the time, half of the places I resigned from left me on the roster anyway (like the HTTPd server project itself).

or even further, naming some of the relevant positions (for example HTTP Server project management committee)

How peevish can you guys be?