I'm not getting what exactly you're looking for - some RTG cards (my Merlin for instance) have a video input and an integrated switcher, so that when a native screen is up front, the card passes the input to its output, thus showing native video. In combination with a FF you can use a 31kHz+ monitor for everything. Without a FF you'd need a 15-31kHz+ multiscan monitor.
The CV64 doesn't have a VGA style input, but it sits in the video slot and deinterlaces the native signal on its own, so you won't need the A3k 31kHz output.
If that answers your question.
