Core Shell 3 embeds a part of Powerline fonts.
While I were dealing with Powerline fonts, I noticed that not all Powerline fonts were patched properly. For example, Meslo Slashed for Powerline and Terminus for Powerline could not recognized by Core Shell, since they lack fixed-width font attribute.
This may be the main reason why you didn't see some installed fonts in Core Shell.
Another thing worth to mention, Core Shell won't refresh the installed font list for you, so you may have to relaunch Core Shell after installing new fonts.
I'd like to keep this topic open, improve the font loading mechanism in future releases.
Thank you very much for helping.
Yang