"Additional 13C can be bred via CNO reaction path ( addition of 2 protons to 12C + decays ) - See here"
That seems unlikely: Since the pads are soaked in heavy water it would be a deuterium environment rather than a hydrogen environment. There's some H in the D2O, but would that be enough? The CNO cycle wouldn't run on D as the first step in the cycle would produce stable 14N if that would in fact be the fusion path. Similarly 14N with D would produce stable 16O.

As for the symmetry in the double spots. We have a difference of opinion/observation/belief there. I guess some algorithm would be better at recognising symmetry without expectations and could supply a degree of certainty along with the observation. Bare in mind the 'entry' and 'exit' spots could be different looking: if this phenomenon is analog to solar flares for instance, the symmetry would be in the magnetic field lines rather than the plasma that roughly follows the pattern. Macro symmetry with localised asymmetry.

It would be awesome to see the diamond lite up with rainbow shaped 'electron flares' (if that is what happens). What would that even look like? And how would the magnetic field generated by the heater coils interact with these dynamic structures? Would it bend the donut shape? Also, why would the structure curve back to the surface to form a half a donut shape?
Looking forward to seeing more!