see https://pasteboard.co/I806Aef.png
its like a narrow spike, but the turret properly shoots in kind of 45 deg arc
Alos not sure if the turrets should shoot the walls that are in front of them? (Iv only testes the shotgun but it looks like it damages your own walls)

No Idea about the attack radius narrow spike, nothing has changed on the mod. Have you reported this as a bug to factorio?

Shotgun turrets do damage your own walls, the cannon turn allows for roughly 3 walls around it.

fixed in factorio 0.17.24

cool, thank you for the update.