I just polished the primer pocket of a Lehigh plug and one from Knight with 2000 grit and JB bore paste spun on a drill bit. The Lehigh plug didn't really "need" it but the W209 primers slip in and out easier now. I pulled randomly out of two boxes of W209 primers and some go in very easy and some a little harder but all of them will work great.

Polishing the knight plug made no difference with any W209 primer. The primers have to be pressed in pretty hard and have to be pulled out with a tool. The last time I used this plug at the range I had a primer get stuck in the breechplug and could not be pulled out with the bolt normally. It definitely needs to be opened up more. Hopefully, Lehigh will start making plugs again or Knight gets their stuff straightened out.