I tried booking for the same time period and found virtually no J or F so I locked in Y+ out of SFO although in looking at the latest treads, last minute (1-14 days before departure) availability seems to be better of course through LAX (which has more flights) and oddly enough YVR which only has a few flights but seems to open up more J/F seats closer to departure than SFO which seems unusually tough even last minute. My problem (and yours too I suspect) is that if J/F opens up at the last minute from a different gateway, the positioning AS segment may no longer be available. For me, based in PDX, it might be worth it to drive to YVR for a J seat rather than Y+ out of SFO...not sure yet though--hopefully there would be some last minute award space available.

With that said, I'm too cheap to pay for an EF subscription so I just check the British Airways website at least twice a day