Hello, its actually a bug in regard how openrouteservice is setup.
The environment variables in the docker-compose.yml are never used by tomcat because this part in the docker file sets them to empty string.
RUN echo "CATALINA_OPTS=\"$CATALINA_OPTS\"" >> /usr/local/tomcat/bin/setenv.sh
RUN echo "JAVA_OPTS=\"$JAVA_OPTS\"" >> /usr/local/tomcat/bin/setenv.sh
Its actually quite hard to debug because the content of setenv seems to be specific to tomcat only. So when you look inside the container the global environment variables seem fine, but are overridden by the content of setenv.
On top of that. Starting with empty java_opts makes the process just take 1/4 of the available ram.
So this poor soul is using a machine with over 120 gb of ram just to run North America because eventually 1/4 of ram was enough:
So my quick fix was just commenting those two lines out. This obviously breaks building the image directly. I can do a pull-request with an more elegant fix next week, but should be easy enough to fix regardless.