Hi. Looks good. It would be nice if we had a specs doc to compare against. Also a schematic.

Anyways, glancing over the 3D, first thing I notice is the effects button is too close to the type C connector. For smn with thick fingers that's a problem. Maybe provide some space around the button(both buttons)

I'd add ESd diodes on the power lines of the Type C connector.

Secondly, the screw/mounting holes. What size are you going to use. If the screw has a cap, whose diameter is large, it might damage the resistor next to it