Quote from Paul on March 1, 2022, 12:14 pm

There is a blog about customising the air assist port see MG3 Air assist

There are two commands in G-code M7 and M8 to control ports. M7 is connected to the driver circuit on the board. M8 can be routed instead of M7 to the circuit via a solder bridge and cutting the existing bridge or you could wire the M8 solder bridge to an external circuit (for tech savvy people).