The first gasket does not block that cavity.
That’s what the “x” channel cut into the baseplate is for.

Furthermore....... the PV is not part of the idle circuit....... so open or closed....... does not affect the idle A/F ratio.
So, if the motor is loading up the plugs while idling...... the PV is not the source of the extra fuel...... unless it’s leaking fuel past the gasket or is torn.

But....... you’ll know shortly after you’ve got it running again if you’ve solved the problem or not.