Blender FBX importer via ufbx

Three years ago I found myself speeding up Blender OBJ importer, and this time I am rewriting Blender FBX importer. Or, letting someone else take care of the actually complex parts of it.
TL;DR: Blender 4.5 will have a new FBX importer.
FBX in Blender FBX, a 3D and animation interchange format owned by Kaydara Alias Autodesk, is a proprietary format that is still quite popular in some spaces. The file format itself is quite good actually; the largest downsides of it are: 1) it is closed and with no public spec, and 2) due to it being very flexible, various software represent their data in funny and sometimes incompatible ways.