Found a potential fix today to the A-pillar / dash rattle. It's two fold.
1. It appears that the underhood seal was not installed as engineered as it lips over the undercowl panel quite nicely and holds it down instead of the leading edge being unsecured in any fashion.
2 I went one step further and put a strip of silicone as a landing pad for where the panel lays on the body to keep it from causing noise. Also the panel that this one attaches too in the back rests on the firewall and I did the same thing there with a touch of silicone.
3. Profit??!? So far so good.