Let users know the progress of applying changes that takes long time to apply.

When changing the Target size of a Substance Material's Texture's Target Size, Unity freezes until the change has been applied. (Note: this also applies to any other textures)

The only feedback is the "Apply" button is in its pressed state and if interacting with Unity, you'll get a "beach ball".

Repro:
In attached project (or any other with substances), change and apply a Substance Material's Texture's Target Size to something above 512

Result:
Long seconds will pass before the change is applied.
No UI feedback is passed to the user.

Expected:
A progress bar like when reimporting audio clips after making a change in the inspector/importer.