Thanks, but can you tell a few words about the prerequisites and
limitations? For example, it sounds like this requires a Cairo build
and the use of the ftcrhb font backend -- is this a requirement, or
should it be possible to make it work with other font backends as
well? Also, are there any assumptions or requirements regarding the
fonts installed on the system?
Printers use "postscriptname" defined in a font file while searching for fonts. psname.txt provides a sample of how to read that information from a font backend. It is not mandatory - but its presence will prevent nasty surprises. In its absence, Lisp code uses font file base name. If the file name doesn't match postscriptname, printing might fail - "might" because printer will try its best to substitute a suitable font.
Theoretically, there's no dependency except Ghostscript which does most of the heavy lifting for printing in Emacs. Fonts other than Truetype might require additional configuration as defined in Ghostscript manual.