If the dog is sick, it should be isolated from the others anyway. I fail to see the logic in this for a single dog, as I know exactly how much I am putting into the bowl and how much remains. I've got several in different areas of the house and have had up to a dozen dogs freefeeding, greedy rescue dogs and all. Never had a problem. The only scuffles arise around treats - because I don't freefed those.
Dogs are the same way.
It's like trying to hoard pebbles on the beach. Seclusion to eat is important if the dog is stressed over trying to protect their food bowl from others but without the threat, there is no stress. The same goes for small children. It is far more dangerous to reach in to take away a food bowl when a dog is eating if it is only fed at specific times. The dog fears losing the food and gulps it down or snaps to protect it.