Sure of what? That anything under 24 hours is a connection, not a stopover, on an international itinerary? That the "PlusPoints" price to upgrade DEL-EWR-SFO is the same as DEL-EWR? And that you're making a mistake leaving the miles upgrade request in place? Yes on all three points.

UA not checking baggage overnight (per its published rules) has nothing to do with the rules applicable to upgrade pricing or clearance.