The only concern, I think, would be flow characteristics. I don't see that smoothing edges of the opening would change that any, or enough to really matter. I'd probably do it. I don't recall what a new set looked like, other than normal, but I don't recall seeing any with sloppy edges like yours. I think I'd notice. That said, most all high-mileage precups I've seen had cracks, and I've never had to discard any due to flash-hole cracks.