Raspberry Pi 4, Protoneer RPi CNC hat v2.6 (current), GRBL 1.1. Machine is 600mm X 600mm, though my test engraves are well below max dimensions. JTech Photonics 2.8w laser: https://jtechphotonics.com/?page_id=3819
I’m not sure I understand your comment about Arduino controllers correctly. I understand that they are lightweight, but there’s a number of people successfully using Arduino Mega + RAMPS (not my board, of course). See: https://www.youtube.com/watch?v=gfq60hYdKHM