The plastic containers are no more wasteful than the plates, they all get washed and resided, it’s just the containers have lids as they go in self-service areas. Also the grab and go containers are designed so that you can take them back to your room if you wish (used containers get collected by housekeeping for washing and re-use. There are no single use plastics anywhere on the ship.
Taco bar serves breakfast burritos 7am to 11am then Tacos 12-3pm. I agree that some of the hours don’t make sense as most of the stations are closed for dinner, but they do show the hours in the app and the printed times guide, then the menu shows the options for breakfast, lunch and dinner. It’s also better than it was a year ago, used to close breakfast at 10.30am with very few options available in that hour and a half until lunch and then the same at 3pm, they used to close the entire sweet counter just when we want afternoon snacks.