Probably worth trying, but I'd try toeing them in to cross in front of the listener first. This is recommended by Brian Cheney and John Dunlavy to increase the size of the sweet spot by increasing interaural crosstalk. Either way, too much tilt in or tilt out will kill the high frequency response of the Eros. You can simulate the same effect of toe-in change by moving the listening position forward or back of the speaker crossing axis.
The real way to increase the high frequency sweet spot is to narrow the width of the high frequency radiator element. Harold Beveridge did this best by loading an electrostatic line element into a horn-like waveguide, yielding 180 degree high frequency radiation. You can try this by taping plastic wrap to block off the edges of the panel in vertical strips; start by narrowing the open window to the 10" width of the Isis, and narrow it further if you like the effect. It'll look like crap, but may work. Okay, it'll look like shit, then it will look like crap.
At least it won't be as awful as listening to those horrible B&W speakers. Hey, I'm a paranoid-schizophrenic and I'm afraid that I'm with stupid.