Borer depth is relevant only to designs digitized for Schiffli work. You don’t have to manually change it before boring unless you want a different size to the default. You can, if preferred, change the default borer depth for use with a specific design and/or make it available to all designs as a custom machine format.
Default borer depth is linked to the selected machine format. You can change the default value for a given machine or job type.
The default starting borer depth value is 6 for Saurer and 7 for Plauen machines. If you want to use a single borer depth at variance with the default, simply set a new default.
Optionally, save to the template for future use. You may want to create a new template specific to the type of work you are doing.