I do not have the skillset to make it happen, perhaps someone else does. Perhaps it could even be added as a default ability akin to overcharge with a high energy usage cost(toggle on for large amount of energy/sec or perhaps initial cost and limited duration with a cooldown). It would probably need a max duration and cooldown even with a a high energy/sec cost to balance it into the late game economy so you cannot fly constantly.
I think FAF could benefit from additional upgrades for ACUs, units and structures. I know ACU upgrades have been altered quite extensively by some modders. Would it be possible to create a structure in which units could dock and pay for an upgrade? Maybe normal units could be upgraded just like an ACU? For example, a LAB could pay an appropriate amount of resources to acquire a personal shield, weapon upgrades or some sort of utility like radar. Maybe build power would have to be provided by the upgrade structure or engineers etc.
The game could become much more interesting if balanced upgrades were added to normal units. Many strategy games offer you the opportunity to increase the damage output, survivability and utility of non-commander units. I do not think FAF is the place for a technology tree, although it certainly could be an option.
I believe the best implementation would be to choose to modify the units like an ACU after they are produced, or to have the option at the factory with an initial cost and appropriate changes to costs to produce the upgraded units. Factories could even be retooled specifically to produce that modified unit but at the cost of being able to produce anything else. I think dedicating a structure to producing a more powerful and more expensive unit would add a lot to the game without damaging the uniqueness that is supreme commander.
Upgrades also have the ability to make less often used units customizable to perform a useful role. For example, an amphibious tank could be upgraded on a map with no water to make it a better option. I do not like that some units are rarely used because of them being optimal in only very rare circumstances. A last example, the cybran t1 AA and afew other units like sniper bots can be set to different fire modes. I'd like to see this in more units either as upgrades or always available.