So, based on this post:
I adapted the zwave init file so that it requires the new python-openzwave version. In the dockerfile I added:
RUN sed -i s/python_openzwave==0.4.3/python_openzwave==0.4.4/ /usr/lib/python3.6/site-packages/homeassistant/components/zwave/__init__.py
to the end.
Now, it works. Zwave can apparently be initialized at HA startup as intended.
However, all of my devices were readded with different entity IDs now… I have no idea why this happened…
Is this preventable so that it uses the previously active entites / config?
The files in my config directory have not changed (zwcfg_.xml).