XS_PART_MERGE_MAX_DISTANCE
Category in Advanced options dialog box: Marking - parts
Use this advanced option to define the maximum distance within which identical parts get merged marks. Units are in millimeters. The default value is 1200.
This advanced option is role specific. When the type SYSTEM(ROLE) is in use, the default value is used. When the type MODEL(ROLE) or DRAWING(ROLE) is in use, you can change the value, which is then the same for all users in the current model.