So I ended up purchasing an E+ seat bundle ($165) and reaching Silver. The E+ PQP from my return leg posted today, almost 48 hours after the flight, so factor that into your plans if you intend to take advantage of seating purchases to reach status.
Upon second thought I realized I’m actually not so sure any more about business trips on United in the fall, so it made sense to preemptively spend my own money to secure some status through all of 2023.