The issue is not repeatability but the fact that cooling is inadequate for the TDP, and CPU (reportedly?) runs in thermal throttled modes.

Armchairers' consensus is Apple botched design and CPU is overheating. Idk. Maybe it's intended design as a form of cTDP.

You'll get the same performance, but you'll see a decline in the battery charge when really putting the hardware to the test. I've seen it happen just using a Google Hangout.

Modern macbooks can ship with a 40 or 60 amp power supply, whereas they should have 90 or 120 amp power supplies. They assume, mostly correctly, that the really intensive workloads will complete before the internal battery is in trouble.

> You'll get the same performance, but you'll see a decline in the battery charge

Right, but the initial problem was that full performance wasn't even possible from the battery, regardless of how much charge you were willing to sacrifice.