Lower-limb exoskeletons are emerging as cutting-edge technology to enhance human mobility. Despite recent advances, yet major challenges in realizing effective control system to have synergistic cooperation between the user and the exoskeletons. It can be achieved by adapting the control parameters to the user. Human-In-The-Loop Optimization methods propose to automatically customize and optimize exoskeleton control parameters closing the loop on human performance, such as metabolic cost or muscle activity. However, optimization methods do not consider the user’s preference, that may capture a broader spectrum of factors associated to functional assistance. Considering user preference into exoskeleton control systems could increase functional benefits from exoskeletons use, user satisfaction, adoption, and acceptability of the technology.