The period saw a unification of inverse-methodology with practical surface engineering to optimize functional profiles, supported by advances such as an extended range-modified gradient technique for profile inversion and targeted blade and gear profile modifications. Experimental work on low-pressure turbine blade suction-side profiles demonstrated measurable efficiency gains, while simulations of end-grafted polymer layers under shear and involute tip relief analyses illustrated how surface modifications reduce wear, transmission error, and vibration. This integrated approach created a cohesive framework linking fundamental inverse methods with material and geometry-level surface engineering.