Well, I have to update the pre-configured SD card image soon. Honestly, given the speed RPi image updates, and how fast they are releasing new versions of RPi, it’s probably better to just use an existing RPi image that already works, and follow the instructions here to install the OSPi firmware:
https://opensprinkler.freshdesk.com/solution/articles/5000631599-installing-and-updating-the-unified-firmware
it’s just a matter of running a few command lines.