Use measurements from the same operating window. J/TH equals wall power in watts divided by hashrate in TH/s. Energy equals wall power divided by 1,000 and multiplied by operating hours; energy cost equals that energy multiplied by the user tariff.
A canary is a bounded test on a named hardware cohort, not a miniature proof for the whole fleet. Progress only when the test has comparable before/after evidence, no unresolved stop condition and a written GO/HOLD/STOP decision.
Compare three illustrative operating profiles after the developer share and electricity cost. Follow the calculation with subtitles and a transcript, and check whether your starting revenue already includes the fee.