We haven´t investigated this topic yet. Please note that CONTROLLINO (MAXI and MEGA) are using WIZnet W5100 as the original Arduino Ethernet Shield. I have seen only some articles about Ethercat with Arduino Ethernet Shiled 2 which uses W5500.
I was also learning about whether to go for ethernet or Ethercat but i found that Ethercat is good. First i can’t much about their difference but using VPN with Surfshark coupon code really helped me to read more about them.