I think this is key.

I've been on many domestic flights where I or my seatmate has been asleep during meal service and the FA would wake one of us up and ask if we'd like to eat now or save it for later. Or, they'd just save it for later without asking and ask us if we'd like to eat after they notice us awake.

I think it's all about being nice and being proactive. If you know you want to sleep first and possible skip the meal when it's served to everyone else, let the LFA/purser know this and see if they wouldn't mind holding your meal until later on. If you ask nicely, it would be very reasonable for them to hold your meal.

Re: getting the hot meal "right away", unless they implement something system-wide, I don't think that's going to happen. I think the best one could hope for is to have it after they do the full service. If you have it before, then people who are really hungry (or just love airplane food) are going to want theirs earlier, etc. But waiting to eat later shouldn't be a problem at all, just ask.