What is a music engraver? I could google it, but I would appreciate a music engraver actually telling me vs some random page on the internet.
It happens that I work for Avid as a designer for Sibelius, the leading music notation program in the world. I also run the Music Engraving Tips Facebook group if you're interested in learning more.
It's of the same importance to a composer or musician that the notation is legible and beautiful, as it is to a graphic designer or reader that type and layout are legible and beautiful.
If the GP is interested in the topic, there are great videos by Tantacrul on his experience redesigning the notation font for MuseScore [0] and his overview of MuseScore 4.0's engraving improvements [1] - in particular this second video, concerning mainly layout, shows just how far this CSS approach would have to go to have a truly legible, reflowable layout in the face of beams/slurs/ties.
(I don't want to take away from anyone on the Sibelius team, they're likely even better experts on the subject than Tantacrul is, but as far as I know, they didn't make long-form Youtube videos about the topic! He also likely got the job of leading the MuseScore redesign thanks to his previous videos that critiqued and reimagined the interfaces of music composition software... including older versions of Sibelius [2] and MuseScore [3])
[0] https://www.youtube.com/watch?v=XGo4PJd1lng
[1] https://www.youtube.com/watch?v=Qct6LKbneKQ&t=2004