HDR over HDMI from blackmagic to TV

Hi, I’m playing some EXR files in RV and using an LG C2 OLED as a presentation device through a Blackmagic Ultrastudio 4k mini HDMI. How can I get the TV to recognise the signal over HDMI is HDR?

I found a release update post from RV 2021 that mentioned adding:
into the video preferences box but this didn’t seem to do anything.

Any help is much appreciated,


and I can get HDR working on the same footage and hardware when playing out of davinci resolve. I just need to find out how to send that HDR HDMI metadata flag with RV.