I've read a bunch about upgrade priority but can't seem to find one that relates standby lists vs upgrade lists and which is processed first by the gate agent.

Let's say we are at 45 minutes prior to boarding. I am on a rev fare (P fare, not via TOD upgrade but purchased up front, though I'm not sure there's a difference). There is no P availability on the flight but there is other availability, and seats, in business class. The flight status screen shows availability in the front cabin.

I'm on the standby list.

Presumably at 45 or 30 minutes, the gate agent is going to attempt to fill the front cabin and process all standby customers as well.

When the gate agent takes control, does the gate agent process:
1) The standby list first (people waiting for business seats and are on rev fares)
2) The upgrade list first
3) Random?

I'm trying to understand if I should go to the airport tomorrow for a flight that shows plenty of availability in business class but no P fares, and try to wait on standby. Nobody else is on standby, but obviously lots of people are on the upgrade list. Since I am a rev fare in business, do I trump the upgrade list or nah? If nah, I'm assuming it's not worth bothering to go to the airport.