Hello again @arcqus
In my research I was able to get some clarity on the situation. Basically speaking, when font is absent from the system Desktop Editor substitutes it with the closest available font. In case when Arial is absent, it actually uses Liberation Sans font, but it keeps displaying this font in the Home tab to avoid confusion.
We think that for this particular discussion following enhancement will be a suitable option to inform users that the font was substituted:
It is also importan to note that the font is defined in the default template that is used for creation of new documents and these templates are the same for all types of installation of Desktop Editors.
I hope it clarifies the situation.