While most program interfaces adequately render SDR content for grading, none of them (as of 2021) will accurately render an HDR image, even when your program, operating system, and display all work with HDR. Using an external I/O card or box with HDR support is ESSENTIAL, and there is none cheaper than the Blackmagic UltraStudio Monitor 3G. I picked one up to give it a quick test, and to see where I could use it in my HDR setups.