Tracks support, rolling stock doesn't and where rolling stock does, mostly motive power isn't sufficient enough or has its own problems with regards to ride quality.
that recent modification by CRS is probably why they moved from testing on main lines of IR to some yard in TDL (WDP 4D's testing and certification was done there.)
As such, no track is fully authorized for 180 Kmph action, whether it's NCR or WCR or WR or whatever. one of the many limitations come into picture.