Be very careful with font handling. The default fonts.conf included
does not tell fontconfig to search any directories. The default folder
passed to ASSInspector is ?script/fonts, but if that doesn't exist or
has no fonts in it, all lines will be rendered blank. Yes, even ones
only containing vector shapes. I don't know why.
Likewise, if you plan on opening a new script in aegisub without
reloading the macro, you need to call myInspector:forceLibraryReload( newFontDirectory ) if the font directory needs to change (e.g. you are
using the default and the new script is in a different directory).