I assure you I feel mostly the same. I was always opposed to any new mechanical bosses, besides a mechanical BoC. I didn't support Zoomo's Peacekeeper, even though it was well thought out and brilliantly sprited. These guys are meant to give context to the Mechanical bosses existing.
If you have suggestions or ideas for the Skull, fire away. It is kind of bland. My original design for the Blueprints was really old, and based off of a palette on a sprite by Wooren. It looked horrible. Since then I've learned stuff, and I decided to use a darker shade. If you want to try recoloring them, go ahead, but I don't plan on doing anything to them.
I'm always open to ideas, and I have none for that particular one, so go ahead.