I recently successfully got a PMUA crew (ex-IAD) none the less to execute this. It took having to speak directly to the purser. The flight took off late and I didn't feel like eating (since I basically just had a meal) and since it was a long flight, I wanted to eat much, much later. I opened the menu and noticed that there was indeed the dine based on my schedule option, which I elected. The FA serving my aisle immediately told me, "You need to speak to the purser about that" which I did. When the purser came over, I had them save me an entree of my choice. Serveral hours later, long after the meal service was done, I went up to the galley and asked the FA on duty to heat up the meal. Which they did. Reluctanly. Can I add that I have over the years flown multiple carriers, and on other carriers this is standard issue, and not a big deal. The reason why I pay to fly business is so that I can fly comfortably and arrived refreshed. The old PMUA crew obviously didn't like doing this......( It was painfully, obvious). Dine based on pax schedule is the norm on most long haul business class on any half decent carrier! By the way, I plan to fly the same route ( which I rather not disclose) again in a few months and will elect to do the same thing. I'll report back on my experience.