Using a normalized Vector3 and 1D blend tree with diagonal inputs

Hello!

So I'm currently doing a third person character with 8-way movement, blending from several animations

Some images for reference:

I use separate 1D blend trees for idle-forward-backward states because I don't want certain animations to blend with each other.

My problem now is passing an Vector3 from a diagonal input. The 1D blend tree takes a value from 0-1 with 0.5 being the midpoint. On the other hand, a normalized diagonal Vector returns a value of 0.7 which throws off the animation blending. Is there any way I can work around this?

Any help would be appreciated!