Here is a preliminary 3 pics of the pcb, combined top and bottom layers, top only and bottom only.
Nothing is set in concrete, so changes can be made. The other style module version could also be done.
Couple of points to note:
Obvious one is there is no on-board filter.
The output is through a 1:1 transformer (Coilcraft), this can be changed, but the transformer gives a better output signal both level wise and harmonic suppression wise.
There are some either/or components depending on whether the square wave output is required, these will be explained fully if this goes any further than just an idea.
Most smd components are 0805 sized rather than the smaller size on the current modules.