Just to add a datapoint from my recent SNA redemption:
Lifetime Titanium member, successfully upgraded on a 2 night stay, 1 night was booked using an annual award cert, the other night was a points redemption. 1 SNA used for each night. Upgrades were approved 2 and 4 days prior to arrival.
Property: Hutchinson Island Marriott, Upgraded room: Deluxe Oceanfront Suite, Sandpiper Tower. Stay: End of July, 2019