We have a number of subview types supported by engine. All but one get used: portal, lightgem, mirror, remote (remote should be used since 2.07).
That leaves the seemingly unused xray subview that we should somehow adopt or drop.
It's not too important how exactly the xray view looks like. The fact is it's already there and can me tuned to any desired effect.
I hope to hear from mappers on possible use of it - off the top of my head it could be e.g. a perception potion that shows AI model contours behind close walls.
Obviously It's not going to be one of 2.07 changes, but now is as good time to discuss as any