I am happy to see this project much active here, Reuben. And not
only technically, but also with things that can demand less
technical knowledge of things, by the end users - or even by users
that create a project deriving from a2ps "simple filter function".
Am I imagining something possible, here?
Certainly, a2ps's configuration system makes it possible to add filter functions that are anywhere from simple to quite complex, and the default configuration showcases such filters in several areas, such as printer options (e.g. single-sided vs duplex, adding various banner information to plain text files), processing different file types (e.g. Postscript and PDF, compressed files, image files), and page organization (e.g. printing booklets).
I must admit that I am sceptical about some of these: for example, on a modern system the print spooler should already provide decent control of printer options; but the great thing about a2ps is that a user can set it up in a way that's comfortable for them.