Accessing modded entities

Plugins Plugin Development
1

I’m working on a project where Sponge is running alongside standard Forge mods that add custom entities and blocks.
Is there a way to access custom, modded entities through the Sponge plugin API? (To spawn them or otherwise manipulate their behavior.)

2 
public static void spawnCustomEntity(){
    // The entity's id, you may get this through cmd /sponge entityinfo
    String entityId = "grimoireofgaia:ant";
    // The world you want to spawn the entity
    World world = Sponge.getServer().getWorld("Main World").get();
    // The position you want to spawn the entity
    Vector3d position = new Vector3d(1, 4, 1);
    Sponge.getGame().getRegistry().getType(EntityType.class, entityId).ifPresent(
            entityType -> {
                Entity modEntity = world.createEntity(entityType, position);
                world.spawnEntity(modEntity);
            }
    );
}
3

Im pretty sure EntityType data works fine for modded entities. So to spawn one you would do it like normal, however getting the entity type is as follows

Sponge.getRegistery().getTypeOf(EntityType.class, "your modded entity id");

You will get an Entity object from that however manipulation of custom attributes of the entity is not possible though the Sponge API. You would either need to add them yourself, or just deep dive into the forge code to edit them. However basic manipulation of the entity such as Location is still possible … I think