Hello Tom, export your content from e.G. After Effects in ProRes 4444 in 1080 progressiv!, not in interlaced. Save it on a card, which you formatted in a HyperDeck Mini in HFS+ journaled. The HyperDeck will it play it now with separated key and fill channel on the 2 SDI outputs.
Convert content from other sources with Apple Compressor to ProRes 4444.
Best regards, Anett