If you are moving to location #1, and then use Shift+Force Move to queue a movement command to location #2, your queued movement command will be cancelled upon reaching location #1, and your hero will move to wherever your mouse location is at that exact moment, and continue to follow your cursor as though you’re holding the Force Move button down.
It makes Force Move unusable as a primary movement command.
While we are at it, the “Smart Commands Click Through Minimap” option does not apply to Force Move commands. This is reason #2 Force Move is unusable as a primary movement command.