Printed and installed (with absolutely none of the correct hardware) the "pltr v2" plotter conversion to the old Ender3. Did a quick test and proved that it would work in theory to apply Sharpie as etch-resist for basic PCB production. Have to figure out how to generate the gcode for the mask with a preset X Y Z offset, but maybe I can cheat by zeroing the printer at a certain location. For reference the Sharpie lines are a bit under 1/32 inch wide, which I think will work for SOIC packages but probably not TSSOP. Still very cool. See video.