> The power brick had a 2m detachable line-voltage cable, and fixed 2m low voltage cable. 2 + 2 = 4. I can sit 4m from the wall and charge using only the power adapter that came with the computer.

You can use the very detachable line-voltage cable on your Apple's 60W (or was it 80?) USB-C charger too. The cable is removable at the power supply end.