First time GS here with a question that may or may not belong in this particular thread - apologies if it belongs elsewhere.

My wife and I are presently booked on an economy award saver fare (XN) ticket back from Japan (KIX-SFO) in a few weeks on a Tuesday. Looking at expert mode (below) on the long haul leg, it looks like the majority of the plane is unsold with all of the lowest paid fare classes still being at 9. Simply put, should I put in for plus points now and go on the waitlist for polaris (knowing that we'll instantly clear into premium plus in the interim), or should I wait until the PN fare class opens up to apply my plus points? My experience as a 1K is that the waitlist sweep to clear the upgrades when PZ opens up is very delayed such that someone applying plus points last minute could swoop in and grab an instant upgrade before United clears those on the waitlist. My feeling is that they will soon open up some seats in the PN fare class as we get closer. The same flight the following day (Wednesday) currently has 7 seats open in PN. Thoughts?

J9 JN9 C9 D9 Z9 ZN9 P9 PN0 PZ0 IN0
O9 ON9 A9 R9 RN9
Y9 YN9 B9 M9 E9 U9 H9 HN9 Q9 V9 W9 S9 T9 L9 K9 G9 XN9