I would add a little cereal to his fruit and veggies. I'd also put him on the same eating schedule as the rest of your group. Every 3 hours. I can't even wait more than that for a meal before my stomach is growling.
Mine all get some sort of breakfast at home, then have breakfast here at 8:45, and lunch at 11:45, and snack after nap, usually 3:15-3:30 or so. Baby is on roughly the same schedule, but he only drinks bm/formula, and some days, he changes things up. This baby is only 12 weeks old, though, not 8 months.
Infants that age, I spoon feed their meals (fruit or veggie with cereal), give them sips from a cup in between bites, and then give them the rest of their formula in a bottle. For snack, I'd give him a cracker or two, and then his bottle. He's almost old enough to start transitioning to a cup.
I would NOT discuss gory details with parents. I would just say "hey, you guys don't have to bring food anymore, just formula, I've got it from here. If they ask why, say "well, it's just so inconvenient for you, and in a couple weeks, I have to do it anyway per my regs, so lets just save ourselves the trouble".