I did a hi heat cook Sat. and the packer in the far end of my chargriller smoked at 300 for most of the time, with a couple of 330 degree spikes. Anyway, some of the bark actually tasted burnt, though I didn't reach the tenderness I wanted.
....so from now on....Hi heat= Reynolds wrap...or that's what works for me. Ya'll can do whatcha want, and I know that some claim to use no foil and cook up to 325, but 500 for a pork shoulder is out of the queastion and just plain ridiculous...maybe on a different planet.