Question TextMeshPro - Material Preset option not persisting in prefab once material font atlas has changed

I'm using the Bitmap Custom Atlas shader and changing the Font Atlas under debug settings of the material.

If I create a font asset and a few material presets, I can get any chosen material preset to persist within a prefab.

However, the moment I change any of these materials Font Atlas' - the option won't persist.

I've been trying to debug the issue to see what it might hit in TMP for this but I'm a bit lost.

edit: Quick repro -

• Default LiberationSans SDF font asset - change the Font Atlas to any other texture for now.
• Create a prefab of a TMP object
• Create material preset for font asset
• Set prefabs material preset to new preset, save
• Close prefab
• Open prefab - preset didn't persist

I know editing the font atlas might be a bit of an odd use case, I don't mind doing some custom implementation within TMP to work around it.

 

Prefab seems to serialize property change correctly. If I click the prefab once in editor, I can see the correct material preset.

The moment I open the prefab in the prefab editor, the material preset is lost.

edit:
nvm - found it

TMPro_Private

Code (CSharp):

1.                 // If font atlas texture doesn't match the assigned material font atlas, switch back to default material specified in the Font Asset.
2.                 if (m_sharedMaterial == null || m_sharedMaterial.GetTexture(ShaderUtilities.ID_MainTex) == null ||
3.                     m_fontAsset.atlasTexture.GetInstanceID() !=
4.                     m_sharedMaterial.GetTexture(ShaderUtilities.ID_MainTex).GetInstanceID())
5.                 {
6.                     if (m_fontAsset.material == null)
7.                         Debug.LogWarning(
8.                             "The Font Atlas Texture of the Font Asset " + m_fontAsset.name + " assigned to " +
9.                             gameObject.name + " is missing.", this);
10.                     else
11.                         m_sharedMaterial = m_fontAsset.material;
12.                 }