Font substitution is a major issue for document fidelity, so it definitely deserves a meta bug.
Indication and Information
Bug 61134 - Font substitute name should appear in the font combobox and tooltip
Bug 78186 - Show infobar that fonts are missing and list their substitutes
Bug 96872 - Make it more obvious that a font has been substituted
Bug 64509 - CONFIGURATION: Enhance Font Substitution Table
Bug 91004 - 'Tms Rmn' font should be substituted for Times New Roman or Liberation Serif
Bug 98650 - Fira Mono fonts poor replacement font metrics
Bug 55255 - SchuDruck1 font not substituted correctly
How we plan to deal with various aspects of font substitution.
The google doc that was used to create the blog post in comment 2 that has addition details that wasnt published.