MacSymbolFonts.txt is a list of all Symbol Fonts. Finale detects files that were last saved across platform and must re-encode all non-symbol fonts. Some characters in non-Symbol Fonts (such as Times) are encoded differently on Windows than on Mac (for example, character #247 on Mac may be represented by #233 on Windows).
It has exactly one encoding (character #247 always equals the same symbol regardless of platform). Noteman says: If you intend to use a third-party music font (that is not SMuFL-compliant), you must add it to Finale's list of symbol fonts A Symbol font, with regards to Finale, is a font that is not re-encoded when a document is opened cross-platform. See To globally change a single musical element’s font and To change the chord font. Any new articulations added to the document will display using the selected font, but existing articulations will not be changed. If you choose not to use one of these fonts, you can substitute any other SMuFL music font, but you cannot change it to a non-SMuFL font (and vice versa). Finale's default documents use one of MakeMusic's SMuFL-compliant default fonts, Finale Maestro or Finale Broadway.
The Default Music Font defines which font is used for notational elements like noteheads, rests, tablature, accidentals, key signatures, time signatures, and articulations in a document.