RE: Late checkout
Abroad, it's a little more nuanced. Unlike in the States, I'd actually give the hotel the courtesy (or, face in the case of SE Asia) of requesting it. Almost every time, their reply is "of course," since it's a well-known Globalist benefit. However, on one occasion, a property very politely asked that though I'm entitled to the late checkout, if I'd consider checking out a little earlier where they'll hold my bags and offer me some comped food/drinks. I agreed and all was well. The next time I returned, I think I had gotten better treatment and the best room upgrade I have ever had in all my years of travel.
Since I don't expect whatsoever any sort of gesture or goodwill with American Hyatts, I would insist on the 4 pm, if I needed it. Heck, I'd even stand in the FD and call my Concierge in front of them, if I had to. As I said earlier on this thread, in the States after the pandemic, I'm going full New Yorker on domestic Hyatts.