Does anyone KNOW how this works?

A friend has applied two of his EVIPS to a BOS-SFO n/s for me and my wife in two weeks. There is no X upgrade availability right now, and as the cabin is pretty full, I would expect this upgrade to go to airport control IF I am going to get it at all.

That being the case, I know that Evip upgrades come from the X bucket and regular PLT sticker upgrades come from A. So, is there any difference there at the airport? Will a PLT with an Evip applied to his reservation have priority over an EXP, over other PLTs even if he checked in after them, or will my priority be sorted the usual way (check-in time, etc...)?