I never recommended a $1 poncho for you or others. Better to don a big trash bag than one of those.
Full disosure- a box of heavy duty plastic landscape bags stays in my truck.
In the end your BOB will fit your chosen scenarios.
Mine is a 3-day bag for all (GA) weather and 100 mile hunting boots.
I also have other items legally carried ;-)
My bad; you didn’t recommend the $1 ponchos.
Those garbage bags - great! Fill them with leaves and you have a mattress; cut some eyeholes, you have a dark green/black poncho (with a weird Klan-hood point at the top). A ready-made bivy sack, or the really thick ones serve well to save the floor of a tent...