Hello Ruben Herrera,
Breadcrumb is a control that generally is bound to SiteMapDataSource. There is no web.config settings that you can use to manipulate its behavior. You can create a custom control that inherits from Breadcrumb and add it to your master page. For the built in modules you can easily show or hide the breadcrumb.
If you want to make any other changes you need to implement your own breadcrumb control.
Let us know if there are any futher questions. If there is any particular area you want to modify, please share your idea with us.
the Telerik team