Sorry, I intially misunderstood what you were trying to achieve. Looking at how teleport is implemented it is not possible to achieve the constant speed. The only variables available for controlling the movement are WALK.TELEPORT_TO_VIEW_MAX_TIME and WALK.TELEPORT_TO_VIEW_ACCELERATION, but no combination of values will give constant speed. The movement always has two phases, acceleration in the first half and slowing down in the second.