Have look at this document:
https://kaffelogic.atlassian.net/l/cp/54LYkpQi
Levels are discussed on pages 9-10 and 17.
Also look at your roast end by time ratio setting.
This is the level that the user sets to determine the point on the profile curve where the roast will end. This point is shown as a red square
■ on the roast profile curve.
However, if the actual temperature does not follow the curve, the roast ends when the temperature curve crosses the threshold line (faint red dotted line). Check the box labelled 'Grid' to see the threshold line.
The slope of the threshold line is defined by 'roast end by time ratio'.
1.0 means roast ends at that time regardless of temperature. The threshold line is vertical.
0.0 means roast ends at that temperature regardless of the time. The threshold line is horizontal.
Numbers between 0 and 1 set the threshold line at different angles.
This allows you to make adjustments so that when a roast does not follow the line it should still finish after approx the same amount of development.
You may need to use zones or a corner to get your roast to follow the profile curve you have drawn.