Unless something has changed with the recent refurb, the mug refill at the Dig Site pool is subject to the QS location hours because the bartender fills it. Perhaps they've added a 24 hour drink station now? I can't confirm.
I agree with walk from the Little Mermaid room is further. I'll also caution that requesting Casitas 4 at CSR is just a request, and can often be hard to get. Since the Casitas buildings are closest to the convention center, convention attendees are given priority for these rooms. We've requested Casitas 4 or 5 in the past, and were not successful. For our last trip, we decided to pay for a preferred room which guaranteed us a room in Casitas 1,2, or 3 and it worked out great.