Besides that, have you experimented or looked into the chemical reactions present in the production of ozone?...I had a hunch that within those reactions lies an explanation for what you've documented with increased current in the second spark. Nikola's "Problem of Increasing Human Energy" bit on burning atmospheric nitrogen sounds like a great way to naturally fertilize the land, at the same time it could be a charge donor during its break down...
Corona seems like a flame burning. To touch on your theory of ether, maybe corona is similar to a flame burning the ether into degraded compounds, just as alcohol burns into degraded compounds, but can be distilled and condensed without being burned (conserved)...Fire and corona seem to be intertwined to some degree. Anyways, I might start posting my tesla research again as you've inspired me...
RE: Verifying Tesla’s theory - first experiments