Wife has a paid economy ticket SEA-SFO-BNE in 5 days. I logged in to check her upgrade options. It was 30K miles to upgrade to premium plus (available), or 30k miles + $600 to upgrade to business (waitlist). From the seat map, there appeared to be a large number of business seats available, so I put in for the waitlist. When do waitlists clear? just at flight time, or before? when I booked the flight, I was gold, now silver. Wife has no status. Can the waitlist clear for one leg, but not the other? and if clearance (or NOT) is at checkin, will I still have an opportunity to upgrade her to Premium Plus for 30k miles, if open seats? too late now, but likely was a mistake to get her paid premium plus for $600+ extra on the return...