It's debatable whether this would be an improvement
As posted elsewhere for a similar reason, the current megapack image was only created a couple of months or so ago and it's cut from a high-quality source. While your source is good (and I wish all players had source images as good and easy to cut), I just don't see the point in having a slightly different cut to the existing megapack version and I would much rather see cutters spending time on genuine improvements and missing images.
Apart from the source quality, you should also keep in mind the existing megapack image when making a request. Just because it's a newer image doesn't necessarily mean it's an improvement. I'm not rejecting it, but I doubt whether I'd consider any resulting cut for inclusion into the MP. Just letting you know so you keep it in mind for any future requests