Lots of toe-in, but how much, exactly?

[New Yorker]

How much toe-in is recommended for HB-1 MK2s? I know, I know… experiment. That said, Hsu suggests more toe-in than is typical, and most reviews affirm this. But how much, exactly?

My speakers are toed-in. My listening position is about 8.5 feet away, and my speakers are placed 8 feet apart. From where I sit - with grill covers removed - the amount of far speaker side visible equals - bear with me here! - the width of the vertical part of the black tweeter surround (just the inner "raised" part; not the flush perimeter with the mounting screws). Got the picture?

Put another way, if I extend a straight line from the drivers towards the listening position, they intersect about 15" in front of my head. Is that enough, or should I toe them in further?

Thanks!