Stock my KFZWOP load axis goes to 150%. Since that is a lot lower than the actual load I am running, the ignition efficiency is off, mixture is enrichened etc.

To avoid that I would like to extrapolate the stock numbers to e.g. 190% load. To do that I have used the two lower values (an increment of 10% load from 140%->150%). See attached image from Excel where the green area is the stock values and the orange ones are the extrapolated values by taking the difference between the two above numbers and adding that to the number from the cell above.

Is this the right way to do this? If I look at the map in 3D it looks bumpy to me (see other attachment).

I can see that the standard KFZW actually exceeds KFZWOP. E.g. KFZW is set to 24 degrees at 2000rpm and 80% load. KFZWOP at the same area is 23,25 degrees.

This is not always the case but there are more examples of values that exceed KFZWOP. Is this normal and does it make sense at all?