I've read through the last few years of the thread and am looking for any pointers or tips for this stay at HHV, including what everyone thinks of the chances for a (Covid rules) Diamond to pull a decent upgrade given the current 80% occupancy rates.

I booked through corporate travel (work trip) and got stuck choosing only a resort view room, no other details. My wife is going with again (she missed my last trip to Kauai in Jan) but I took her to Waikiki for a work trip Dec 2020 and we stayed at the Sheraton on the beach provided by the client (the hotel).

The stay is showing all the MyWay Benefits awards like space available upgrades, points, and meal credit based on my current selections. I've never been denied any benefits going through corp travel, I don't think they regard this "3rd party."

Chance of an Upgrade, preferably to Rainbow tower?

They're offering paid upgrades for $69 for out 6 night stay, but the airfare at over $1,200 was already a killer and I'll also be burning a ton of miles for waitlist upgrades on UA. I'd pay if I knew there was no way an upgrade was coming, but would prefer to take a wait and see and save $430. Still not a bad deal since work is paying for the (base) week.

Sounds like the daily credit is now use it or lose it. Frankly, I forgot about this benefit as I try to avoid room charges due to expense reporting/reimbursement hassle of splitting hotel and meals (ugh), and because I use my personal cards, and also stay more often when I travel if there's a Home2 where there's no dining and free breakfast.