It's the first one I saw in help with a split gradient. Perhaps not the best suggestion 🙄 but it did explain why a lower slope of 90' was never really going to work.
The heights are measured individually and vertically, initially from the roof pivot base line to the external face pivot point and then between pivot points for any additional slopes. Depending on the roof type AC will extend the highest roof plane to form a ridge.
Apple iMac Intel i9 / macOS Sonoma / AC27UKI (most recent builds.. if they work)