Considering the original complaint is regarding the other races having repair rates just a few hp higher for a single target, I fail to see how a free area-wide 5hp/sec that's always on is somehow balanced.
The reason I suggested it is because Vasari already have AoE repair ability, so why not be able to tech it for the repair station?
Also, by getting you 5 hp/sec, whichever target was the focus of the repair facility, with it's 15 hp/sec, that target would actaully be getting 20 hp/sec.
I think it also solves the problem that Vasari has of running out on AM, as you can turn off the auto-cast and slowly let your fleet repair while not costing you AM.