I did notice that plate actually, and was tempted to remove it as well. I ended up leaving it as it looked like I would need a welder to make it happen, something I don't have. I was going to say the same thing about the way you welded everything up perfectly! Wayyy cleaner than using pop rivets.. I've noticed that I'll get a tin-ey rattle at idle sometimes which I'm sure is because of the pop-rivets. If I did it again, I would look at installing a stainless baffle in the middle to support the perforated pipes and provide a resonance chamber to help reduce the drone at highway speed. I'ld also look at packing it with stainless steel wool to help clean up the sound. In Alberta, we have a law where you cannot increase the size of the muffler outlet or have vehicles above 93 decibels, so maintaining the stock look was the biggest thing for me, and I think this type of modification is the best balance of better exhaust sound without the annoying volume of an aftermarket system. It also retains the option of fitting the stock panniers. Here's a video of a ride today so you can hear the sound
I like your version too, I think the way that you placed the perf tube over the exit tubes is better. I tried to weld some new tubes on but they did not line up with the back cover so I left them out, however I've got another set to modify now so I will do what you did there.
Did you notice the perforated plate at the start of the Baffle? were you tempted to remove that too? I
Love the sound of it, I too get the popping under deceleration but I love that part of it the most :)