Apple is odd in that it scars heavily if cut while growing vigorously, and does not heal well if cut in dormancy. In my climate, I try to balance this by pruning at the end of strong growth, at the end of summer. Here this is mid September, then slower fall growth lasts until mid October. I'm sure your climate does not afford this 2nd or 3rd growth period.
Maybe, try cutting in a slow growth period, and then scarring during an active growth period. I would heavily advise consulting someone familiar with your growing conditions, as they are vastlyt differently than mine..