Bug report: When exporting to VRM 0.x, T-pose transformation is not applied to shapekeys; lip sync animations could affect arms

[Kakurady]

Describe the bug

When exporting to VRM 0.x, T-pose transformation is not applied to shapekeys; if an avatar with A-pose resting pose is selected for export, viseme animations will affect arms.

To Reproduce

1. Import Avatar with A-pose
2. Pose Armature as T-pose and save to pose library https://github.com/saturday06/VRM-Addon-for-Blender/assets/138435/93c18af0-647b-478c-8ce2-661b6335b683
3. Set T-pose for VRM export
4. Add new blend shape proxy and set a shape key https://github.com/saturday06/VRM-Addon-for-Blender/assets/138435/21da1f25-4eb5-4108-b142-7ca7c3c70318
5. Export as VRM 0.x
6. Import VRM into new Blender file
7. Observe resting pose is T-pose
8. Adjust shape keys value and observe morph target remains in A-pose https://github.com/saturday06/VRM-Addon-for-Blender/assets/138435/d6e2d3b6-b8fb-4aac-9d26-4a4d9b3fa7aa
9. Import VRM into application with lip sync, such as VNyan or VirtualMotionCapture
10. Observe lip sync animations also move arms https://github.com/saturday06/VRM-Addon-for-Blender/assets/138435/49c0f90a-1ba2-4b6b-8481-a961af972ae4

Expected behavior

• T-pose transformation should be applied to shapekeys
• Lip sync animation should not affect arms

Screenshots

Desktop (please complete the following information)

• Blender 3.6.4
• Addon 2.20.7

Additional context

Does not affect VRM 1 export.

Does not affect avatars already in T-pose.

[saturday06]

Thanks for reporting!

Dangerous bug. I will fix it.