Eh actually the xclamp is a horrible design, it pushes up in the middle of the bga and with enough heat cycles will give the rrod. The xenon consoles are pretty much the only ones that do this because on all the other boards the cpu and gpu are glued/epoxy to the board.
Xenon boards will warp and cause either the cpu or gpu to throw an error. The standoffs are too high and need to be sanded/pushed down .75mm.
You can see what happens in this illustration.
The hdmi boards are different the zephyr gets more gpu and ram issues than anything, and the falcon gets mostly ram issues (rrod 0102). If you ever send a xenon board with rrod to ms they'll send back a falcon board without an hdmi port (i like to call this the zombie board).
Anyway with my fix the board is held in 8 locations in the middle along with the screws on the outside. As long as it's all even and there's nothing warping the board it's a better solution than the xclamp. There's just so many different versions of the xclamp and only a couple of them are permanent solutions.
360C for one minute? Ever destroy a board like that? Ever have a Capacitor explode due to extreme heat?
That's 680F and it should only be that hot for about 15-20 seconds max. Hope you preheat the underside to about 350F before attempting that. It only takes 440F to reflow the solder but a lot of reflow tutorials go that high. They go up to 360C for 15 secs after everything is warmed up then down to 290C for a min then down to 90C then off.
I guess if it works and you don't destroy anything it's a fix.