While a direct "port" of the popular Enhanced Camera mod from Skyrim or New Vegas does not exist for Fallout 4 due to engine limitations , several mods "simulate" a visible body by manipulating the third-person camera or using unique scripts .
For a smaller immersion boost, this mod on Nexus Mods adds visible arms and hands during running animations, which are typically hidden in the vanilla game. fallout 4 see your body in first person mod
Works on Xbox; lets you see your full outfit and holstered weapons. Top First-Person Body Mods While a direct "port"