Well, for LVTO we need the required RVR for all parts of the runway. Are you saying it's acceptable to have RVR 250 m for the stop end when the required VIS/RVR is 400 m?
It's usually CAVOK when I'm flying so it's my first time encountering a situation like this.
To me it's not crystal clear so I'd prefer to err on the side of caution.