Some miscellaneous things:
Not sure how often they do it now, but the torch lighting ceremony is always lovely. The fire dancer from the luau does it.
Get the Twilight Feast!! It’s ‘Ohana dinner as room service. It’s a wonderful treat and something you can only do as a Poly guest.
Most beautiful sunrises and sunsets on property, imo. Take the resort launch to MK at twilight at least once.
Semi-covered patios at the Oasis pool can be booked for a nominal fee. They’re not cabanas per se but are very comfy.
The Grand Floridian is a short and scenic walk away and worth checking out, especially if you’d like to try signature dining, the one thing Poly lacks. Poly guests can also use the fitness facilities there because they’re technically shared.