I've also applied PP well within 24 hours a few times this year (so sort of monetization) and gone from 6+ back on the list to F without ever showing as upgraded.

And several times done SDC onto flights with PZ after clearing CPU on a different flight, also snagging seats out from under the waitlist.

What I've been surprised by is the number of flights showing PZ2 (or more) within a few hours, sometimes within an hour, of departure while still having long upgrade lists. And even on a couple of occasions, when I was still waitlisted with PP (canceling and reapplying the upgrade request cleared them).