Since these already existed due to my various attempts mucking with it, sure:
Added to ShipAPI:
Vector2f getShieldTarget();
void setShieldTargetOverride(float x, float y);
Sets direction for omni shield to face
Needs to be called every frame
However, we NEED a way to control omnishield and accurately rotate the ship at the same time.
Well, a lot of the time ship damage is a matter of flux, so taking a few seconds to shield while not firing doesn't necessarily even mean a decrease in overall damage. That's not to say that having a method to do this wouldn't be nice; I think we just differ in how necessary that is. In my personal playing, I've never found it to be a truly pressing concern - but I certainly understand and respect that opinions on this will differ.
I've got to admit I'm rather torn on this suggestion.
I play with inverted controls most of the time,meaning mouse aims and A&D strafe since my fleets usually employ frontsiding units more than broadsiding ones.
If I happen to play the latter kind of ships I switch to normal controls so that I can control ship manouvering with A&D, strafing with Q&E and shield directioning&weapon aiming with the mouse.
Directional Omni shield controls would allow a player to not have to switch between the two control modes when changing command from frontsiders to broadsiders and viceversa and just stick to the former, but I don't see the utility of it for one simple reason:
How many frontsiding ships actually have an omni shield, and how many of them actually keep it in favour of converting it to a frontal one to gain better protection and lower their shield upkeep, justifying this suggestion? I can only name a very few amount of vanilla examples that would benefit from this suggestion, and it would mostly amount to absorbing Salamander missiles that would otherwise hit your engines.
Now don't get me wrong, I'm a very strong advocate of more customization and giving as much ship control freedom to the player as possible, but manually directing Omni shields can already be done in one of the two control modes and frontsiding ships that also have an omni shield are usually big and sluggish enough to not make their directional control with A&D a task that can only be accomplished by a Meth addicted squirrel on both Redbull and Cocaine.
Now, the true suggestion for me that would solve this problem would be to give us an actual hotkey that switches between control modes. I'm playing with a standard 2 boutton mouse and a Razer Orbweaver
Spoiler
(https://images-na.ssl-images-amazon.com/images/I/71EvQpoY5wL._AC_SL1500_.jpg)
What I'll conclude this reply on is that I think the most useful feature OP talked about here is having your omni shield track a targeted enemy for you, while the player still retains the ability to raise/lower the shield at will. The icing on the cake for this "auto-shield" would be making it able to also track missiles, like the dreaded Salamanders that gruesomely doomed many of my non-360 shield frigades.