Accessible studios are a bookable category, so you can ensure getting one by booking that category (select the option "Show me Accessible Rooms only" during the booking process).
Choices for accessible studios at Poly are:
Deluxe Studio – Standard View, Florida Special Accessible Room with Option for Hearing Accessibility
Deluxe Studio – Standard View, Wheelchair Accessible with Roll-In Shower and Option for Hearing Accessibility
Deluxe Studio – Standard View, Wheelchair Accessible with Tub and Option for Hearing Accessibility
Deluxe Studio – Lake View, Wheelchair Accessible with Roll-In Shower and Option for Hearing Accessibility
Deluxe Studio – Lake View, Florida Special Accessible Room with Option for Hearing Accessibility
Deluxe Studio – Lake View, Hearing Accessible
Deluxe Studio – Lake View, Wheelchair Accessible with Tub and Option for Hearing Accessibility
Sorry, I'm not familiar with where these rooms are to give you any specific request advice.
I can tell you room 3921 in Tokelau is an accessible room. It’s a standard view studio on the 3rd floor. The bed is lower, there are some handy rails, there is both a bath and a shower. There is an actual freezer and fridge. The studio seemed bigger than others we have been in at Poly but I’m not 100% sure. It definitely felt bigger than the studios at other DVC resorts. I would happily stay there again.
I've never seen a lot of reports on PVB accessible studios. There do not seem to be many that are fully accessible so it depends on what accessible room type you have booked. I can only add that there is a ground floor roll in shower in Pago Pago that faces the north/garden side. I don't recall the exact # but I'd say it was located fairly centrally in the building.