creo4 config.pro option documentation for: BOOLEAN_DEFAULT_OPERATION 
show_total_unfold_seam
Controls display of seams (the edges of the cutting plane) in total unfolded cross-sectional views.
Default and Available Settings:
yes*
| Displays the seams (the edges of the cutting plane).
|
no
| Blanks the seams (the edges of the cutting plane).
|
