Documentation for Pinctrl

From the official product page as well as various answers on this forum, it can be gathered that the UP Xtreme i12 is confirmed (and intended) to work with Ubuntu 22.04.

On the other hand, several libraries for GPIO access which are currently recommended by the documentation only work with Ubuntu 20.04 and earlier:

• mraa
• upboard-extras

As such, I can only assume that their functionality has been completely replaced with pinctrl. That's fine, but here's the problem:

There is seemingly no documentation whatsoever on how to use pinctrl beyond installing it. How can the product be available before the documentation is ready? I just bought something I can't use...