I considered adding another upper brace on the right side, but sometimes overkill is just overkill. All of this fits behind the stock plastic, none is particularly visible, nothing touches or rubs on anything, and it's still 100% removable. I claim success. Now there's almost no movement in the windscreen even if a lot of force is used, and the little that there is is clearly coming from the rubber mounting of the screen itself. Total cash outlay: 0$.
Oh yeah, all welding was done on the bike with spare welding gloves acting as my welding blanket. I could have made the welds prettier if I took it off, but like I said, there's a lot going on inside that front end and it wasn't worth the hassle.