Looking for a consensus............
While vibration damping under the rear seat, I am wondering what the consensus is on applying mat to the two circular access panels to the gas tank filter and pump?

Both panels seem to be reasonably solid when you tap on them. Definitely not nearly as hollow or tinny sounding as the surrounding floor board, so can't be as critical to do, just wondering what is commonly done.
Leave it or mat it?

As far as sound deadening, it seems easy enough to lay some foam or some of the other multi layer products on top of the mat as extra air born noise absorbtion.