I’ve decided to move a moderately sized site over to Hugo from Joomla, at the moment I have not got the site live.
However, I have a conversion facility written in Java that gets all of the categories, tags and content out of the database, structuring it into directories that match the categories in Joomla. Leaving only the template, static content and plugins / extensions to be processed manually.
Although it is a bit rough and ready, it may save someone doing a Joomla conversion considerable time. It is hosted on https://github.com/davetcc/hugojoomla
If the SEO friendly option was selected in Joomla, then the URLs that are generated on publishing should match up out of the box. It also cleans up any internal links and introtext descriptions. Once I get my site fully live, I’ll update and I guess at that point it can be considered complete.