As the map markers and grid colors in the screenshot show, energy is not split up between metal extractors properly. The grids energy limit (total solargen output) has not been reached.

The energy-to-metal ratio, which is represented by the grid color should be the same for both grids (hence the color should be the same too). This is not true in the given example - nowhere near.

The mexes default output was ~3.2 vs 1.something.

What makes you think it should be same? It depends on extraction ratio of the mex! Optimal distribution is not everywhere same, it depends on base extraction.

You obviously misunderstood the problem. The energy to metal ratio SHOULD be the same for all extractors. I am not talking about the Overdrive-%-number, but the energy used/extra metal ratio.

Yea it does seem a bit off. If you want you can check the solution to the energy distribution equation.

But otherwise the energy distribution seems to be doing it's job. It doesn't have to produce the most efficient layout, just make it so adding pylon links isn't a bad thing. It's doing this in all but the most extreme cases. In my tests connecting an extra mex to a grid of a mex with a large income is a loss of income less than 0.1%.

So it's not really a high priority, anyway it would make the large metal spots even more powerful.