If you add defensive-structure to the HarderA.do_not_touch_list in functions.lua then it should skip all the vanilla turrets. If you're using a mod that adds turrets then you'll need the subgroup for those turrets.
Keep in mind that recipes are baked into any save games, so if you change the recipe you also have to enter this into the console to overwrite the recipes in any previous save.
/c game.player.force.reset_recipes()
