I have attempted to free up the ShadowMaps VRAM usage by destroying the light source inside a scene, as it was outlined in Max's answer. Sadly I had no success with it.
Here is a test-project:
You can destroy the lightsource by pressing the middle mouse button.
When destroying the light source I can see no difference in the Shadowmap VRAM usage in the PlayCanvas debugger (open with CTRL + ALT + T).
I tried to delete the entities in the scene aswell, but this also made no difference.
What additional step do I have to take to clear up ShadowMaps usage in VRAM ?