Decal texture are stored in the decal atlas even if all "Affect XXX" settings are disabled

Steps to reproduce : 

• You can use the attached project to check the issue
• Or setup a decal project that affects transparent, with textures assigned in the decal and disable all "Affect XXX" settings
• Display the decal atlas in the rendering debugger.

 

See that all the textures from the decal are stored in the atlas (you can enter / exit play mode to force a clear of the atlas), even if not used as all the "Affect XXX" settings are disabled.
The only exception is for the base color texture, as its alpha channel is still used for the opacity.

Reproduces : all versions