Using 3rd party apps - Kickr with climb - erg mode


To get round the Climb not working in Zwift’s workout mode, can you pair a 3rd party app (TrainerRoad or Suffestfest) to control the Kickr in erg mode while riding in free ride mode on Zwift?

That way the Climb will work as normal but the erg/power is controlled by either SF or TR app?