Stamp of approval; hmmmm.
Each ATC (with the exception of the group nerd, most have them) needn't and doesn't undertake his own reseach or spend hours investigating the safety of the standards & procedures set before him by those with the duty to do so. We just apply the procedures.
If we encounter something that doesn't seem to work or pan out the way procedures say they will (such as separating aircraft by distance reports in a particular way, but subsequently see a bit less than expected on the radar...) there are ways of reporting this that are difficult for anybody to sweep under the carpet. We are required to do this.
Many moons ago towers would not approve intersection departures, now they do. It can be demonstrated that an intersection departure involves more risk than using the full length, but pilots & ATC can justify this (before the Coroner if neccessary) as the actions of a reasonable person.
The same applies here. I follow the procedures that somebody else has established as safe and I am protected by the deep pockets of that somebody.