Click here for a description of the method on the SpeedSolving.com wiki
Initial discussions for the method started in March, 2017.
https://www.speedsolving.com/threads/the-new-method-substep-concept-idea-thread.40975/post-1222720
The method was officially proposed a few days later.
https://www.speedsolving.com/threads/the-waterroux-3x3-method-thread.64140/
WaterRoux changed from FB > SS to FB > no blockbuilding after the left side 1x2x3 block.
https://www.speedsolving.com/threads/the-new-method-substep-concept-idea-thread.40975/page-199#post-125159