I just don't have time to maintain the stylesheet factory right now. Its sole intent has become to build the default stylesheet (until we have a suitable replacement). So filing issues against it won't be a good use of
If someone wants to make a successor to the stylesheet factory that's maintained and more consumable to users, I'd support that effort.
The information about the stylesheet factory has been removed from the new documentation site, so the docs will reflect the current situation once they are published.
At the end of the day, the stylesheet is just CSS, so you can create it however you want. The stylesheet factory was designed to make that a bit easier, but given how outdated it has become, it's actually making it harder. Hence why I don't recommend it anymore.