Area Mex Command
The Area Mex command queues construction of metal extractors in a given area.
The individual constructions are ordered from the nearest mex to the builder in the area to the farthest, disregarding obstacles - for this reason it may be better to queue several Area Mex orders to guarantee an optimal builder walk path.
Holding ALT while placing an Area Mex order will place 4 solars around each mex in the area. This protects the extractor and provides Overdrive.
You can use the ALT modifier for adding Solars to existing metal extractors as well.