Bug report: Node Group value does not apply after export

[miramocha]

Describe the bug

Output from node group value is not applied prior to exporting. In the screenshot below, file exported should have yellow rim color which comes from output of node group instead of purple which is the original color prior to linking input color from nodegroup.

To Reproduce

Steps to reproduce the behavior (with the screenshot above):

1. Set parameteric rim color input of MToon to purple
2. Create node group with color output to yellow
3. Link node group color output to parametric rim color input
4. Export VRM file
5. Open the VRM file in Unity runtime or web based app
6. See that rim color is purple instead of yellow

Expected behavior

VRM exported should have yellow rim color or any other value from nodegroup

Screenshots

Desktop (please complete the following information)

• OS: [e.g. Windows, macOS, Ubuntu Linux, ...]
• Blender 4.0
• Addon Version 2.20.18

Additional context

Not sure if this is a bug or feature request. But fixing/adding this will allow us to change color one time and have them apply the value globally to all materials.