I have split the mufflers open cold with pliers, drilled and grinded all holes in the birdcage/baffle more open but kept it, maximized the stock outlet while keeping the ability to use the stock spark arrester screen, re-crimped the halves back together - voila, stock looking modded muffler.
I like this mod on my PS-7900 so much I duplicated it on my PS-7300.
My PS-6400 and PS-7310 still have stock mufflers.
All my saws are stock!
Modded outlet
View attachment 120471
Split, before modding
View attachment 120472