Thank you again for the feedback and duly noted about the "tool library" (Help files) which will be increasing in size with revisions and additions as we all progress.
Regarding the burn time at zero volts, remember how we are testing and measuring the secondary firing voltage. (Using a near non contact, capacitive pick up COP probe or pick up leads)
The beauty of the capacitive pick up is that they measure the “Electrical field” around a component.
Using the capacitive pick up enables you to sense this field around non-conductive components such as “Coil on Plug-COP” units.
The strength of the electrical field is dependent upon the current flow and activity through the component. Given we do not have a hard wire connection to the secondary coil we are reliant upon the electrical field to produce our signal/waveform.
Hence, we see the "Polarity peak", some activity during the dwell period, the rapid induction into the secondary, oscillations, burn time, and coil ringing as we then climb to our zero volt point to start all over again.
In the image I have posted, the scale has been increased 3 times to provide more detail, can you try this technique with your capture?