Hello James,
The BSP does not support this resolution software wise.
However, it would require a Pixel Frequency of 297 Mhz, which is well within the limits of the controller and within the CEA861-F Timing Summary (table 15-6 of the Reference Manual) valid frequencies, and this resolution is should be supported by the HDMI 2.0a standard, so the hardware should be able to achieve, you would need to work on the software implementation.
I hope this helps!
Regards,
