This companion consolidates the geometric and scaling conventions required for the 5D-to-effective-1D reduction used in NJSR. It provides canonical definitions of length scales and sign conventions, clarifies what is baseline vs deduced vs postulated, and documents the reduction pipeline from 5D structure to the effective variables used in Paper 3. The goal is to prevent ambiguity in dimensional hierarchy and to provide a stable citation target for all 5D-to-1D mapping statements.
Igor Grčman (Mon,) studied this question.