I don't think any of this matters much. You might get a little nicer treatment as *Gold though.

I assume you have a longer layover at SFO if you're looking to change to an earlier flight. When you get in, find a customer service agent, and ask nicely if there's any possibility of putting you on the earlier flight. If there's space, the agent may offer you a change, or offer you standby. You may not get to stay in F.

If you only get standby, wait until the gate opens up, and try again with a gate agent.