Cons will most likely get well deserved buffs for their support abilities from the commander patch. Their support currently does not scale wich is weird considering it should be their defining feuture.
I don't think that T4 upgrade help them much. It's almost like run to uphill, where from the start to lategame you must survive until build T4 and get this upgrade. While in the other side you have penals from box, they are work from start to end and have good scale in lategame.
If we want make cons really support unit and keep penals as more expensive offensive unit, we can change cons from terms of resource effectivness, not their battle states. As i suggusted before in previous topics about cons:
1. From 1-st buildnig (T1 or T2) you get global upgrade to speed up reinforce for cons.
2. From medics upgrade you get upgrade on cheaper reinforce for cons (16 mp instead of default 20).
3. Replace flare mine to faster sandbag building.
Their decreased cost and time of reinforce will make ability Merge more attractive to use than now . Fasten sandbag will show them as defensive support unit and help play through T2.
These changes don't make them good fighters, but get to SU player 2 options: openning from cheap and fast to return on battlefield cons (without any real additional investments), or more expensive offensive oppening through penals.