The actual blocks are a mechanical limitation of the mount. So there is no way to actually get them to traverse to the point where they would hit the ship. Naval designers didn?t want some excited 19 year old manning a 20 mm gun to swing that weapons in and hose the ship with fire while tracking a target. It would be easy enough to do while peering through a Mk14 gun sight or looking through iron sights. So at a certain point the mount just hits a point where it won?t swing any further. If you somehow removed that limitation assuming it is possible to do in a practical sense the gun would fall off its mount.Does that mean that by default they aren't engaged?
About the only weapons you had to worry about hitting your ship upon launching them were the hedgehogs. I?ve heard stories about how if the weather was rough enough you?d have trouble. If you launched in the bottom of a trough and the bow pitched up as you launched the mortars would sometimes collide with the bow. Now the mortars armed while in flight so there wasn?t much thread but having that amount of TNT or Torpex bounce off the bow must have been disconcerting. Other than that you could potentially blow off your fantail with depth charges if they were set too shallow and you were going to slow.