What happened to the Property Matrix?

In the Content Browser, “Right-click” > “Asset Actions” > “Bulk Edit via Property Matrix…” no longer appears to work with certain asset types like Materials or Material Instances.
I’m like 99% sure this used to work before 4.9. Am I doing something incorrectly?

Hi Jake,

The property matrix has been disabled for Materials, Material Instances and Material functions as they require very special handling because of their dependencies with the rendering thread, and they don’t have a good paradigm for updating ‘anywhere’ as they rely on talking to and flushing the rendering thread. We’d have to make some invasive changes to the property matrix in order to make them work correctly. Sorry for this inconvenience.