Nice! As far as that screen goes, I was wondering if there were any small gains to be had without opening up the muffler. A few years ago I uncrimped another muffler, gutted it and opened up the exit hole a bunch. It didn’t really seem to cut any different but was ear splitting loud. So I ended up getting another stock muffler.
Whether you use a screen or not, whether you use a stock muffler or not, please, please use adequate hearing protection. In your later years you will be glad you did. We know enough now to avoid the mistakes of my generation. Those who do not know history allow history to repeat itself.