Ethyl pyruvate has been on my radar since last year. Someone on reddit (presumably healthy) posted that they took a supplement which had Ethyl pyruvate as the main ingredient and got amazing cognitive improvements from it. Sadly that supplement is no longer available, and the only other sources I can find are research suppliers.
I'd also like to try a non-calcium based source of regular pyruvate (doesn't have to be ethyl), just because whilst I do well with pyruvate, I don't do well with calcium, and all the pyruvate supplements seem to be calcium pyruvate. Pyruvate is one of the few mito boosters that actually does what it says on the tin.