ATCs is where the Acorn board may struggle for IO.

Taking a Triac ATC, it needs 5 inputs (Carousel In, Out, Up, Down, and index sensor) and 5 outputs (Carousel CW, CCW, In, Down, and drawbar) for the ATC alone.

That only leaves 3 and 3.
Input wise, allow one for E-stop/limits (combined on Triac's), one drive fault, one for a probe, and you're out of inputs.
Where do you connect the homing switches/sensors?

Output wise, spindle CW, CCW, coolant, and you're out of outputs.
I'm assuming the drive enables are a separate output on the step/dir headers, if not you're definitely short on outputs.

I will say the software does look good, and it could be the best software in the world, but if you can't get enough inputs and outputs, it's useless.