On the Statendam, the Lido usually did not have food available for the hour or so before dinner as they were getting ready. Now with the no self serve policies, I don't think it will be available. I also don't think the hamburger, hot dog, taco bar is open at all times. Not sure about the lounge treats. We found if we got back after the afternoon tea snacks, that we had to wait until dinner, which worked fine. Most port days we were rushing back to get on and get ready for dinner and or deporting.
I think the "no self serve policy" was just in effect when the Norwalk virus was going around. We were on in April and it was serve yourself as usual in the Lido.
After the official hours in the Lido are over, they have wrapped sandwiches there, and I think the ice cream bar is still open at that time. There is always fruit around, you can always bring some to your cabin to eat whenever you want.