No sign of detonation on the piston(s), and as there are three bent ones it may simply be an overdose of torque rather than a problem in one cylinder. OTOH injector duty cycle was very high at max revs WOT, could have leaned out/bad batch of fuel, but lack of evidence of detonation suggests cause was something else. Possibly abuse from a PO, but again no real signs of that. Car has done two uneventful track days on this tune, knock started first session of the third track day.
In other news, after much searching I finally found my Singular bonnet louvres, hidden away in a box labelled 'Singular hood louvres' ...




(When I dropped mine off at Mania, David showed me one that died of alternator failure - the rod literally came out and knocked the alternator off!)