So in case anyone ever finds this thread and wants a data point to consider, four upgrade seats "magically" appeared on the leg to Australia (SFO-BNE, mid-December on a Tuesday, so farther from peak holiday travel) about 7 weeks out and we grabbed them. We are still waitlisted for 4 seats on the BOS-SFO outbound leg. As of approximately six weeks out from return leg (1/2, SYD-SFO) the seat map show 11 available Polaris seats. I did transfer the points to United and joined the waitlist today for the return trip and have fingers crossed it will clear.

While the seat map isn’t an exact tool, if there are only 11 seats available on the seat map six weeks out, your chances of clearing are approximately zero. :(

Especially looking for four seats

I'm pretty sure no more upgrades are in your future. SFO-BNE is far easier than BOS-SFO and SYD-SFO. I guess if you have GS status, you might luck into an odd seat or two out of the 8 total you're looking for on the two flights.