Not really. You can use priority setting.
Resources (both metal and energy) get spent in 3 priority queues: high, normal and low.
First, any caretaker, con or commander set to high (as well as units that consume energy to regen shield, cloak...) takes what it needs from high priority. If any resource remains, all that takes from medium take what they need. If anything remains, all that is set to low takes what they need. If anything remains, it goes to excess (which is good for energy, but bad for metal).
If at any point one of the priority queues draw more resources than are availalbe, they split available resources (by I think total resources / total build power) and the lower priority queues get NOTHING.
I guess what I'm trying to say is if you want something to be completed first, you can have the cons/caretakers set to high priority and they will always work at maximum capacity.
I changed the default caretaker behavior in my client. It has low priority. That way, any con/unit that needs resources takes them over caretakers instead of splitting resources. This allows cons to build something asap, but still share among at least factories so unit production doesn't go full stop.