Did you know: you can give orders to the ACU to complete a hydrocarbon power plant, BEFORE the first engineer even comes out of your first factory? And then, even before this first engineer comes out of your first factory, you can queue up further orders for the ACU to follow after the hydrocarbon (which has not even been "ordered" yet) is completed.
Replay ID is: #12190093
This technology is the "assist" order which can be placed on the ground, before you give the order to manufacture a hydrocarbon plant there.
Clearly, this is a vital technological advance that must be adopted into the meta immediately. Waiting until after the hydrocarbon is under construction to give additional orders to your ACU is suboptimal. That is the OLD way of doing things. Now you must all conform to the new meta.
Further, this technique can be used to give engineers orders to assist with another engineer's hydrocarbon plant. No longer must you wait until you have an opportunity to select 3 engineers at the same time so you can tell them all to build the same hydrocarbon plant.
In fact, you can place the "assist" order on the ground BEFORE OR AFTER you have given the order to a different engineer to manufacture a hydrocarbon plant there.
Replay ID is: #12190172
Perhaps it would be an overstatement to suggest that this is the new meta. But it should be a useful trick to keep in mind if for some reason you are experiencing difficulties or interference with the habitual synchronization of engineers to cooperate on building a hydrocarbon plant.