We are redoing the hardwood floor in our entrance area and we have a return vent outlet. Currently the cover (register) is raised up to the wall but the actual hole is only on the floor (See attached picture). I mean the return vent pipe is not extended to the wall. We were thinking to replace the cover that is flush with the floor and not raised on the wall as currently this is a minor obstacle on the way. But we are not sure if this is allowed according to the building code and not against the best practices. We were wondering if any one has thought of doing such thing before or if you have any thoughts.