Someone should write a utility that makes asset pipelines repeatable by allowing modification through scripting during the j3o conversion process.
…oh wait… they did. 
JmeConvert tool
Getting stuck in a position where “I need to make an edit in my j3o because it would take too long to rebuild my asset” is a bad place to be. Way better if you can just go gltf->j3o in some easily repeatable and easily tweakable process. jmec is meant for that.