Basics

A Sink with multiple nozzles close together (and perhaps aimed at a common point) each for different modes
Some kitchen models have this for sprayers

User:Eric Rant + Idea

Basically it would have the following nozzles:

Ultrafine Mist for light hand cleaning
Standard Airator Nozzle
Rapid Flow Nozzle for Filling Applications
Sprayer Nozzle for Sinks etc (most usefull if a removable tube head is in use as well, otherwise just essentially a mess maker)

This would allow for the water saving when possible, while still being able to do more intensive tasks, or bulk filling tasks

It wouldn't be needed in most applications, and would introduce some complexity, but IT'S SOMTHIN