My experience with ALL late check out benefit as Platinum last year was quite poor.
Most hotels only able to provide 1pm late check out.

The only hotel that consistently provide late check out was Raffles Bali where they match the late check out time with my onward flight even when the flight was 6pm.
They claim that DPS airport have nothing to see so I better spend more time (and money ) on their resort.

Sofitel Legend Hanoi also manage to provide me with 4pm late check out.

Will have another stay at Raffles Bali in about 1 month time, followed by Raffles Singapore.
Usually the Singapore one is not very generous with late check out, but then people certainly don't mind to have extra couple of hours exploring Singapore Airport anyway.