Today I figured out an issue that has been blocking progress on StratosERP for a while. Its one of the last things needed, and I had run out of other immediate bugs/features, so it had to be sorted.
After some debugging I found that my local dev wasn't setup correctly and symfony wasn't aware of the reverse proxy, and was giving http instead of https urls.
Sorted that with some changes to the docker-compose.yml but... still same problem.
Back into the debugging and tried hardcoding the path with the docker listening ports instead of the public sort of ports and Woohoo - success.
After a little more tweaking I came up with a nice small patch and posted it on Drupal.org as Allow wkhtmltopdf to work in docker/kubernetes style env.
This means I can continue using my favourite PDF generator with the only penalty being a slightly larger docker container.