Having “donor halos” are not ideal and doesn’t have to do with scarring, it’s simply due to donor depletion. I have noticed a similar issue myself. I truly believe this is due to larger punch sizes and harvesting too many of the multi hair grafts. A huge reason of getting fue is to be able to wear your hair short. But when you have areas of your donor that look like they are harvested at excess of 50%, it looks unnatural and you can’t wear a buzz cut because when your donor is patchy compared to the rest of your hair it simply doesn’t look natural. In addition, larger punches have the possibility of “collateral damage” by transecting nearby hairs.
the above poster is right, clinics like asmed have pristine donors for the most part as they utilize the smallest punches they can (and I assume their punches have a small wall diameter as well).