Video monitoring for different aspect ratios

[dockyard g67459400]

I'm trying to set up a cleanfeed monitor using the Decklink 4K Extreme 12G card. For 16by9 sequences that works great, but 9by16 results in no output because it's not supported. Are there any monitoring options (like in DaVinci) to re-pack the signal and handle mismatched resolution/ratios? If you set one of your monitors in the playback preferences that seems to work just fine, but I'd like to find a workflow with the external video card.