Actually, yes, that absolutely has bearing on the issue of feeding. It has a large bearing on it, as a matter of fact.
The fact that snakes stretch out immensely (esp. in the head/neck region) makes a injury in that area difficult to heal. Esp. a "rip" or large wound. The fact that they "constrict" and quite hard at that, can also make wound healing difficult. Esp. a big open gash.
I do remember your thread.
Honestly, to me it looks like your snake lost more then just scales. It looks like skin was removed as well. Even if that heals without stitches (and it will be a while) any stretching in that area can make it re-injured.
I'm surprised the vet didn't want you to come in for that. I've seen missing scales before, but that looks like missing skin and and quite the large portion.
Honestly, I wouldn't feed just yet. You haven't had that snake for very long and he got quite the injury. Let him relax and heal some more.
Once you do feed, feed small meals. Way smaller then what the snake should normally get. Nothing that is much bigger around then the snakes body where the injury is. You don't want the skin to stretch during eating, not until it is healed, at least past a shed cycle.
In order to better help you, could you post another picture? In good light, clear and close up ? Also the exact location how far down the body.