Facing a $300 dilemma.

Waitlisted LHR-SFO two weeks out on a W. It was wide open when I booked a month ago, but we're now down to 11 open J seats on the seatmap (btw, when did UA change the mobile site so you can't see number booked?).

LHR-ORD-SFO has now opened wide in R all the way through, 763 connecting to a 772.

$300 to confirm the change. Who would pay now vs. sweat it out to T-25 and hope that R opens on the nonstop (or remains open on the ORD connection)?

Edited to add: I just figured out that mobile site still works to check bookings, but only the text version. Booked 29/40, which matches seatmap exactly.