At 30 Hz can be selected between RGB and YCbCr444 and font will appear as usual.
Unfortunately, the use of fall as a monitor so flat for me and I will return the LG.
The Samsung UH6900 / UH6950 is said to have the same problems as safe and viable alternative then remains only the not yet available Philips BDM4065UC (with DisplayPort 1.2 and 60Hz 4k with 4: 4: 4 color).