Best to grab a few opinions on this, Marty.

Some like to install the mylar on top on a shiny playfield with a high polish of Novus 2.

I prefer to have good adherence, so I always use Noves 2 to "preview" the imperfections (if any). The I clean the novus OFF with shellite. The Mylar will have its own shine - part of the composition of mylar - is a nice shine.

I'd be worried that the chemical composition of Novus, left behind, would cause issue with the mylar adhering.