The default hotkey for "Baneblade Front Artillery Cannon" is 'V'. This disables the use of the default factorio feature of flipping buildings vertically.
That's unfortunate. I mean you still can change the keybind but I think I'll change the default to Shift-V anyway. I could also stop the game from blocking firing the mirror event but I don't want anyone accidentally firing the gun when they just wanna mirror their blueprint ^^
