@elextr,
I had a thought while inspecting that filetypes files should include all lexer property settings, even if set to Lexilla default or commented out, since Lexilla only code-documents them.
The [SciTE website](https://scintilla.org/SciTEDoc.html#DefinedVariables) lists every known property, including lexer properties. To your point, though, it's not very searchable.
Lexilla maintains a Python script to keep the properties table in sync with code changes:
https://github.com/ScintillaOrg/lexilla/blob/43ea736569d52ba6cf7e7325cf39009...
#2517 was an attempt to automate the extraction of property info from release tarballs.