I don't really know why this is all on a CVA thread but here is my opinion anyway....
I use to have a disc extreme and a disc elite with the standard fpj breechplug and I had 100% ignition. In my mind the reason to switch to the Lehigh plug was to minimize the blowback and keep the breech area so much cleaner. I would spend a fair ammount of time cleaning that area after a session of shooting bh209.
Unfortunately, and it may have been purely for legal reasons, I think the Lehigh plug took a giant step backwards when they brazed in the ventliner and made in non replacable unless you have Ron's capabilities to drill it out and make it like the old Lehighs.