On a positive note, SNA’s are not completely broken. I used an SNA at the Marriott Momi Bay in Fiji to go from a basic room in a block to an overwater “bure”. It’s like an entirely different hotel and the process went smoothly with my reservation showing up as an Overwater bungalow on check-in.
In terms of how improved the room is, this could be the best use of SNA’s I’ve yet found in the system (things like Gritti Palace base rooms are hardly terrible even if the suite is even grander).