There is a very slight cornering gain to be had by tying the towers together. They will at least deflect the same amount, less than what the outside tower would do by itself but more than what the inside tower would. This benefits the more heavily loaded outside tire more than it will hurt the lighter-loaded inside tire. It's one of several compliance-camber things, and for strut tower deflections it's pretty small. There might actually be more actual improvement under extreme braking where the tower tops are moving in opposite directions, compared to the same-direction movements they have during cornering. A strut tower brace really isn't a suspension component but a chassis component that has the potential to affect dynamic behavior (and certainly the NVH that basically tries to hide what's going on down at the contact patches).
Better tires help more than just about every other handling mod, it's where the rubber meets the road... As far as strut braces go they're really not needed on the race to work and back and they probably wouldn't help at an auto x event. They do the least for handling when being compared to every other suspension components . So the stock struts are "tied" together, big whoop. The chassis isn't any stiffer and the struts are the same ole struts.
I have edited post #53 to clear up a likely misunderstanding. Norm
'08 GT coupe, 5M, wheels, tires, pads, fluid, a few suspension mods . . . still almost stock height
'19 WRX, 6M (the "family sedan")
'01 Maxima 20AE, 5M (the spare and occasional winter driver)