This paper introduces two new geometric contributions to the Watch Fit Geometry Framework. First, the Total Wearing Height (TWH) is formally defined as the complete vertical envelope of a wristwatch on a wrist: TWH = T + CT + WD, where T is strap thickness, CT is case thickness, and WD is wrist depth. Second, Comfort Axis 5 — Cuff Clearance — is proposed, formalizing the geometric relationship between TWH and available cuff clearance: TWH ≤ CD − ε_cuff, where CD is cuff internal diameter and ε_cuff is a comfort margin. The paper demonstrates that the common watch reviewing phrase "slides under the cuff" is geometrically imprecise — it conflates at least four independent variables (CT, T, WD, and CD) into a single subjective observation. Comfort Axis 5 replaces that phrase with a precise, measurable constraint. Five open problems are identified: a CD dataset, ε_cuff empirical validation, WD measurement standard, bracelet-specific TWH geometry, and dynamic cuff clearance during wrist flexion. Both TWH and Comfort Axis 5 are designed to roll up into the forthcoming unified Watch Wearability Framework. Related publications: DOI 10.5281/zenodo.20447375 (Axis 1), DOI 10.5281/zenodo.20449108 (Axis 2), DOI 10.5281/zenodo.20514259 (Axis 3), DOI 10.5281/zenodo.20496426 (Fit Vector), DOI 10.5281/zenodo.20496410 (Framework), DOI 10.5281/zenodo.20514293 (Comfort Framework v1).