It’s not possible to share fonts across documents as it would result in the incorrect appearance of fonts.
PDF files commonly use font subsetting, which means that two fonts with the same name could contain different glyphs.
We also commonly see variations in mappings and metrics, which means that two fonts of the same name may map characters to different values or have a different appearance.
The woff files generated during conversion are created from the fonts embedded within the PDF file.
The id after the font name refers to the object reference of the font object within the PDF file. This ensures that fonts of the same name in a document do not conflict, but will not prevent conflicts across multiple documents.