This one is rather incredible:
He added the possibility of using two of his control modules together (in this example FluidNC and Estlcam, but any two work), you can switch between them with a little switch. This is incredible. I for instance would use it to control the CNC when cutting things where the 2m USB cable is not enough, just switch to Fluid, do the cuts and off you go. Programs with toolchanges etc. are a lot easier with Estlcam though.
I do not need it right now and it would not fit my control box, but I am pretty sure it’s going to find its way into my CNC one day.