Suggestions about Mega-equivalent with built-in Ethernet

Nice routing, Jon! I'm sure that was a ton of work.

I might be totally wrong about this, but I have seen PCBs with a vRestrict area under crystals because a via under a crystal will be in contact with the crystal's metal case. There is a via under one of your crystals (connected to GND I believe?). Just thought I'd mention it in case it was not intentional.