I was just using the Line Place command, and it occurred to me that it's currently rather cumbersome to use: It requires two clicks to create a line to fix the orientation, and then another to set the position.
I think it would be easier to use if the first click fixed the position, and then the shadow-formation rotated (always keeping the turrets pointed toward the pointer), becoming fixed by a second click. This would allow dropping the turrets with one fewer click.
I suspect it could be made even easier to use by incorporating click+drag mechanics to define an area to fill with turrets.