HDR does not look good After upgrading macOS to 10.15.4 on my Macbook Pro 2018, an HDR option shows up for my 4K BenQ PD3220U display. It is even pre-selected.

I can tell that the display is definitely in HDR mode. Unfortunately it does not look very good. The fonts are weird, as if they aren't antialiased. It is especially noticeable in black-on-white text.

Is there a way to improve the HDR mode?

The display is connected through USB-C. Changing resolution to Default for display does not help. I have used this display in HDR mode with ChromeCast Ultra so I know how good HDR can look.
I have now realized that what I was seeing was the typical halo effect of high sharpenss. The image examples in this article illustrates the effect perfectly.

Decreasing the sharpness from 10 (max, the default) to 1 (lowest) improved the fonts immensely. Even 5 is pretty good, but as far as I understand it sounds from forums like the lowest setting is most faithful to what the OS wants to display.