Thanks for the tips above re hyphenation. Sounds like there is no way to work this into a headless / script-based workflow, i.e. based on invoking ebook-convert command-line?
I'm aware of the Python "hyphenate" script and the suggestion posted here
https://www.mobileread.com/forums/sh...d.php?t=274246 , but the script hasn't been updated for recent Python releases and even after making a few fixes to get it to execute, I'm still not able to get satisfactory results. The Hyphenate This plugin works great but doesn't appear to be scriptable. Is there any relatively simple solution to that?