Start of the rocket should not give inertia to the launcher. Very big inertia in launcher top. Now the launcher always receives inertia from start, and does not depend on your situation. So should not be.
There has to be a dependence on position of the shooter. In position of a body standing - a certain coefficient of inertia, in situation on a knee inertia is less. The clamped right mouse button has to reduce influence of inertia at start of the rocket, is relative for each position of the shooter. Possibility of a support on a fence or other ledge is absent. It as much as possible will reduce inertia of the launcher.
All this is necessary in those cases when there is no opportunity to launch the rocket on homing. Can be such purposes infantry, the building, the equipment is not completely visible when homing does not fix the purpose when the shot over open sights is necessary.