[nhma]

The voltage of the powerline is not relevant since the charging principle is based on inductive coupling. So as long as you have a current above ~100A the harvester should work, irrespective of voltage. And high currents equal higher charging power.

To optimize charging time, the drone could perhaps analyze the magnetic fields to determine which line has the highest current to optimize charging time. But I would assume some sort of balancing is happening between the lines and phases.

The powerline used is a custom mockup with just 5V AC. But we have also landed on real powerlines. I think there's a video in the channel of the OP video.