So, I tried adding a recipe called...
branchyleaves.json
{
"ingredientPattern": "LS",
recipeGroup: 1,
"ingredients": {
"L": {
type: "block",
code: "game:leaves-grown-*",
name: "type"
},
"S": {
type: "item",
code: "game:stick",
}
},
"width": 2,
"height": 1,
"shapeless": true,
"output": { type: "block", code: "game:leavesbranchy-grown-{type}" }
}
This allows me to make branchy leaves from sticks and leaves. I humbly submit it for the next mod update.