Godot: Broken material reimport for GLTF2

[MrOneTwo]

Godot version: 3rc1
OS: Windows 10

Issue description:

After changing material parameters in Blender and re-exporting asset the material doesn't update. Changing Keep on reimport in Reimport tab doesn't change this behaviour. The only way to circumvent it is to delete material and reimport.

Steps to reproduce:

Create an asset in Blender and export it according to this article: https://github.com/KhronosGroup/glTF-Blender-Exporter/blob/master/docs/user.md .
Import it into Godot. Change material's parameter and re-export. The material in Godot won't update.

Minimal reproduction project:

gltf.zip

[capnm]

Can confirm, it's still broken after rc2 1699978e2458487824882e01449da271dee7f89f

It works once or twice after the godot start (if you are lucky).
No matter which import material settings are set.

Edit: It doesn't seem to be just material-related, changing the scene / mesh sometimes (but not so often) has the same problem.

Edit 2: The collada importer has the same issues.

@MrOneTwo the included blender file is unusable outside your hard-drive, you must append
(not link) the gltf node tree.

[reduz]

This is intended. If you want materials to be updated from Blender, change the import settings to built-in,
otherwise Godot will leave those for you to edit and will not update them.

[capnm]

What is the Keep on reimport option for?

[Linko-3D]

This is intended. If you want materials to be updated from Blender, change the import settings to built-in,
otherwise Godot will leave those for you to edit and will not update them.

I think it would be much better to be able to update the model, UVs, texture and materials automatically by default, because this is the advantage of the glb/glTF, it's like syncing the model from different software and get the same result like we do with other game engines. Also if we work with placeholders and want to iterate this gets very annoying.