All these threads are tangled in my mind, so ... -a: I use this quite regularly for quick peeks at line and page breaks without the trouble of writing a file and looking at it in another window. It is certainly the option I type most--the rest are buried in shell scripts.
separate maintenance. macro languages suffer from being almost write-only. It's only a slight exaggeration to say that each package requires its own special expert. I would favor separate maintenance, with the maintainer filing a regression test. The groff maintainer need only run all the regressions and check with the package maintainer on failure. It's helpful to ship a small bundle of macro packages with groff, just as a small bundle of fonts is shipped. But specialties (e.g. chem) would best be available for download from the groff website rather thancluttering the distribution. I would like to see font files as downloadable packages, too. Doug'
