Support for it was offically dropped a long time before 1.0.16, but the setting was left in the config app, and some people were lucky enough to have it continue to work.
The PVR350 TV Out only worked with the old 'GBPVR.exe' though. This is no longer distributed with the app (I think 1.0.16 was the last to include it). The new interface is PVRX2.exe, which has no functionality for using the PVR350 tv out.