[1.19.2] How to set visibility of Geckolib geo.json part?

I am using Geckolib to create custom entities, but I want to be able to enable/disable certain parts based on criteria. For example, a saddle layer would only show if the entity `isSaddled()`. I'm just not sure how to access individual model parts using the geo.json files.
For now, I have created two separate models and I swap them based on the `object.isSaddled() method`:
 

@Override public ResourceLocation getModelResource(MyModdedEntity object) {

return MODELS[object.isSaddled() ? 1 : 0];

}

Edited December 10, 20231 yr by Darwinagain
adding codeblock