A little set of actions I made converting between the specular and metalness workflows with a click. The Specular to Metalness conversion is essentially flawless and maintains PBR accuracy whilst the conversion from Metalness to Specular is somewhat lossy due to the nature of the workflow but also remains fully PBR accurate albeit with a small loss in value range and and an assumed specular value for all dielectrics. This is unavoidable.

The accuracy of the output assumes input maps within accurate range, further information is provided in the readme.