Not read the whole thread, just came to give some ideas based on the facilities at your workplace. Ignore if no longer relevant.
Jacket potatoes: all cooked the night before a few days at work. Or even just when you've got the oven on and frozen ready. Can be left in the fridge for a few days and grabbed as you go out the door. Various fillings work, beans/tuna/cheese etc. All easy to batch prep, say on a Sunday night ready for the week.
Micro rice with your choice of protein mixed through. I pick up the supermarket own ranges in various flavours and add either cooked (by me) chicken, mixed beans, diced chorizo, chopped pork etc. Add some diced veggies or some peas. Sprinkle of cheese maybe.
Pasta salads made on the Sunday night for a couple of days. Loads of fillings you can choose from. Tuna and salad, pesto and pine nut, roasted veg and feta....
Soup, homemade or tinned. With a cream cheese bagel or a sandwich. Add some yoghurt and some fruit.
Batch some bolognaise and freeze in portions to grab.
Lunch at work is the highlight of my day to be honest, so I don't mind the effort of doing some prep on a Sunday evening. I also don't have kids to sort. No judging from me if it's easier for you to grab a meal deal, so what you gotta do.