Is HDPi suport not working on the editor?

I’ve read that the Unreal Editor 4.15 features support for 4K monitors (HDPi).
However seems not to be the case on Linux. Here is what I see:

I can’t scale the DPi value because it says to me that it is a problem regarding the “DefaultEngine.ini”:

And the options available here (application scale):

don’t save as default and seem to make the icons look a bit blurry:

Is HDPi recognition not yet available for Linux or I’m doing something wrong?
Best regards

The message about not being able to write DefaultEngine.ini is unrelated, but as of now, there is no HiDPI support in Linux UE4.

Understood, thanks!