Initial_robot_pose overwrites any prior information the robot would have.

[WilliamDubois]

When you pass an initial robot pose as parameter with the map you load, you need to know to exact heading of the robot to which you want to load the pose, including the random initialization of the yaw from the madgwick filter. It would be nice to have the option to give the exact complete pose (for LTR) and the option to update from the pose that is computed by the mapper using the TFs before processing the input. For example, in my case I needed to input only translation while keeping the heading, but it is impossible right now.