Hi @rowanhopkins98 ,
You can continue to export your baked single representation of a surface. You can continue to use the same parameterisation as before, we have a MetalnessToDiffuseAlbedoF0 conversion node.
F0 is the surface reflectivity in itself. Previously it was computed from Specular and Metallic, however that parameterisation can have the downside of showing color leaking when lerping from dielectric (metallic=0, F0 in [0, 0.08]) to conductor (metallic=1, F0 >0.08 up to 1). See this. With F0 now this artefact gone and we then enforce energy conservation between specular/diffuse according to F0.
In the end moving from specular/metallic to F0 parameterisation should be beneficial when representing a single surface with dielectric and conductor all together in a single layer without any color leaking.