I don't think this has been discussed yet.

So, in the books, Voldemort goes to the Potter's house in Godric's Hollow to murder everyone there. He uses the killing curse on Harry which rebounds and also takes down a lot of his house and Voldemort's whole body. This curse, which doesn't leave a mark, rebounded and took down a house and a whole body.

The killing curse rebound in the forbidden forest is way tamer. There's no big impact mentioned (the death eaters seemed fine). Harry and Voldemort just drop dead. Voldemort's body is completely whole as well; he didn't need another ritual to rebuild his body.

I've reasoned that Harry didn't get another scar because there wasn't another Horcrux trying to lodge in his head.

I'm fairly sure the inconsistent effects of the killing curse rebound is due to the writer and for dramatic effect.

I'm still interested to see if we could come up with a good reason for the difference between the two rebounds