I'd love to hear about alternative solutions that don't require Windows, and still spit out colour-accurate CMYK indesign files; the printing shops won't accept anything else.
Most printing shops I've had to treat with will also accept PDFs, is that the case? Because then, there's a case to be made for converting your templates to HTML (gives you access to a huge amount of tooling) and printing them to a PDF through a headless browser instance (like pptr.dev). That has worked for me in the past, and is accessible and good quality (though I did not need accurate CMYK, so YMMV).
(Though browser-based PDF isn't a panacea either. We've got one customer whose 250 page technical manual needs between 40 and 70 minutes to generate through paged.js and Chrome… They're fine with running it as an overnight job, but it's still painful to watch.)