Hi,
Converting Principled BSDF materials from Eevee/Cycles to Octane I've encountered few issues:
1. BRDF model is set to Octane instead of GGX
2. Coating parameters are not converted.
3. Sheen value has Alpha enabled.
4. Transmission is not converted
5. Emission is not converted.
6. When there are few objects with the same material the converted material is not replaced but new material is created and other objects still have old material.