What glb compessions (optimizers) can I find?

[Mugen87]

You can use Draco, a library for compressing and decompressing 3D data. There are different ways to compress an existing gltf or glb file, for example via gltf-pipeline. More information about this topic right here:

A .glb model loaded using GLTFLoader isn't compressing despite using DRACOLoader

As @Mugen87 says there are two steps required to use Draco compression: Compress the data during or after export. The Blender exporter cannot do this for you, so you’d need to take the glTF file created by Blender and use it with https://gltf.insimo.com/. There are other tools for glTF->glTF+Draco conversion in progress. To load a glTF file using Draco, you need to give GLTFLoader a DRACODecoder so it can decompress it. Looks like you’ve done that part correctly above.