Hi Hexx_Vixtar, no need to finish the game to comment, this helped a lot. It wasn't the shift-click: an earlier update cut Frontier down to one deploy column, so the line stopped growing. In v0.5.15 Frontier II and III are back, one column each, so your line reaches farther toward the archers again.
Thanks for reporting, you're on the credits page: https://marrowmarch.com/credits/