So, in this episode of discussion Time my mind came up with an option to limit XI7's.
So here is the idea. Engineering commands!
Now this seems to be the "duh" option but hear me out.
Instead of just repairing shields what a player can do is move shields.
So since you can only redirect 1 point of damage you can move shields from the side of an ISD/VSD to the HZ being attacked to continually present a strong zone.
You can move 2 points and repair a point and be good.
Thoughts?
