[css-nav-1] Consider candidates on the navigation direction.

I want to resolve some unreachable cases caused by current spec about determining whether the candidate is on the navigation direction or not.

In the below example, Let's assume that user press right-button from A/C/E.

B and D is reachable from A /C.
According to current spec and chromium, F is not right side of E

*Spec :
https://drafts.csswg.org/css-nav-1/
-> "the item partially overlaps with searchOrigin and its two edges which are orthogonal to dir should be on the navigation direction of the respective ones of searchOrigin."

*Chromium : https://cs.chromium.org/chromium/src/third_party/blink/renderer/core/page/spatial_navigation.cc?q=spatial_navigation.cc&sq=package:chromium&dr&l=117
static inline bool RightOf(const PhysicalRect& a, const PhysicalRect& b) {
return a.X() >= b.Right() || (a.X() >= b.X() && a.Right() > b.Right() &&
a.Y() < b.Bottom() && a.Bottom() > b.Y());
}

I hope to remove "a.Right() > b.Right()" part.
Is there a problem if User can go from E to F using right key?
I would like to know your opinions. (@jihyerish @frivoal @hugoholgersson @Bokand @anawhj )