The latest incarnation of the Empire Mortar rules dosnt state that the multiple wounds (d3) special rule is just under the centre hole like like other 'stone throwers' so does the entire template cause d3 wounds?

It does say that it is fired as a stone thrower so we could say that the special rules are for the centre hole only but does that mean Armour Piercing is also just for the centre and not the entire template?