In the "Result Window Definition" under "display Options" tab, you can choose how many level the legend has to have.
For default they are 9, but you can choose 15 levels.
You can choose number of levels also in Format > legend: in the right you have the same controller for the number of levels.
Sorry, now I have undestand your question.
I don't know if you can change them. I haven't find any option that allow you to modify number of significant figures.