PhysicalCam Viewport DOF setting?

When dof is on, the viewport displays the blur using the camera target…anyway to change the viewport setting to use the focal distance instead? I know this isn’t directly vray related, but since chaosgroup helped develop the physcam, I thought someone might know.

This is for max 2016.

Unfortunately it doesn’t seem possible. It seems that it is hard-coded to control viewport DOF using target distance.