How do I exclude this plugin from affecting sulfur gathering and pickup?

you should look at the config file

set Enable Sulfur Ore Gather to false

you can disable collectibles by setting them false:

    "Collectible Entities": {
      "diesel_collectable": true,
      "berry-green-collectable": true,
      "potato-collectable": true,
      "stone-collectable": true,
      "metal-collectable": true,
      "wood-collectable": true,
      "sulfur-collectable": true,
      "hemp-collectable": true,
      "berry-blue-collectable": true,
      "berry-red-collectable": true,
      "berry-white-collectable": true,
      "berry-yellow-collectable": true,
      "mushroom-cluster-6": true,
      "mushroom-cluster-5": true,
      "halloween-wood-collectable": true,
      "halloween-sulfur-collectible": true,
      "halloween-stone-collectable": true,
      "halloween-metal-collectable": true,
      "halloween-bone-collectable": true,
      "pumpkin-collectable": true,
      "corn-collectable": true,
      "berry-black-collectable": true
    },

you can disable an entire skill by setting it to -1

    "Level Caps": {
      "ACQUIRE": 200.0,
      "CRAFTING": 20.0,
      "MINING": 200.0,
      "SKINNING": 200.0,
      "WOODCUTTING": 200.0
    },

if it isn't a config option then you can't do it