Hi Rob,
What do you actually want to achieve here?
If you want to compile xquery files to protect your IP I have no idea how to do that. Saxon has such a feature in a limited way if you buy PE or EE if I remeber correctly. You can call Saxon using xslt:transform.
I do a lot of docker stuff and I * used a JVM image and mounted everything BaseX (so the zip distribution including any xquery code I added) * tried to create a buildpack that downloads everything needed and creates a container form that: https://github.com/simar0at/heroku-buildpack-basex This is a https://github.com/gliderlabs/herokuish buildpack (usabel with gitlab CI/CD). It is still rough around the edges
Maybe you want something in between?
You probably will need to mount <basexHome>/data (which also contains the logs), and <basexHome>/webapp containing any code for the (rest based?) services you want to provide.
Best regards
Omar