This early draft uses ESP32 and a HR911105A RJ45 connector. I want to attempt using LAN8720A as Phy. The Hat will contain SPI as backbone, CAN as secondary control, an USB, Wifi, Bluetooth and Ethernet.
The schematics look straight forward, but I have a lot of reading up to do.
ESP32 is as fast as many of the modules I have shown and it can be extended to use modules with more Flash and RAM.