More capabilities for custom mobs, custom blocks, biomes, and dimensions

Addon creators need more block and mob coding access to make more advanced addons which would allow players to make their own custom machines that would have custom inputs and outputs. having custom furnaces and chest would be amazin and creators being able to add bosses as powerful as the ender dragon or stronger would be amazing. It would be awesome for creators to also create their own dimensions and custom ways to transport into the dimensions for example maybe a pattern with creeper head can take you to a creeper dimension that contains it's own species of creepers. If these capabilities were added creators would be able to use their creativity more