Custom Create Mechanical Crafting recipes not showing in game

I'm attempting to make a mod or datapack that replaces the standard Immersive Aircraft recipes for ones that require Create mod ingredients. 

I have all my Create based JSON recipes done, and then using KubeJS, I have disabled all Immersive Aircraft recipes. When I go in-game, I can see my new recipes for the sub-items, think boiler, gyroscope, sail etc, but for the big items, where I want to REQUIRE a mechanical crafter array, they do NOT show.

Im at a loss, and not sure what to do next. I have written, and re-written the recipes in different orders, I have validated the JSON files with no errors.

Here is the recipe for the biplane:

{
  "type": "create:mechanical_crafting",
  "pattern": [
    "   S ",
    "S  S ",
    "HH_EP",
    "S  S ",
    "   S "
  ],
  "key": {
    "H": [
      {
        "item": "immersive_aircraft:hull"
      }
    ],
    "E": [
      {
        "item": "immersive_aircraft:engine"
      }
    ],
    "P": [
      {
        "item": "immersive_aircraft:propeller"
      }
    ],
    "S": [
      {
        "item": "immersive_aircraft:sail"
      }
    ],
    "_": [
      {
        "tag": "create:seats"
      }
    ]
  },
  "result": {
    "id": "immersive_aircraft:biplane",
    "count": 1
  },
  "acceptMirrored": true
}

Any suggestions would be greatly appreciated.

Thanks.