Alexandru Tenie/Deformat here. I've been searching for some alternate fonts, since the original font (Open Sans) didn't have extended language support. I've fount out about Intel's Clear Sans: https://01.org/clear-sans I've noticed that for normal text Clear Sans Medium could work rather well for various text (as you may test it here: http://www.fontsquirrel.com/fonts/clear-sans). For lockscreen, a more light version could work, or maybe the current font could work as well.
I'd like to point out that there are also various other fonts with extended language support, such as Ubuntu's font and Firefox' Fira (Firo?) Font. Alexandru/Deformat
