For every standard and custom business object there is the ability to add custom logic at the header and item level of the business object. This custom logic can be triggered by specific events (exits/BADIs) such as on load, after modify, before save, and BO save/validation for the BO header and item level.
On some standard business objects there are additional exits/BADI provided for scenario specific exits/BADIs that have been requested by customers (for example on the ticket there is a BADI to control the visibility of UI components when the agent workspace UI is loaded). A complete list of all scenario specific BADIs are available in the repository explorer in SDK.
So it is supported and very simple in C4X to execute custom logic when an item is added to the quote or ticket during after modify (when the item as added) or before save (when the item is saved to the quote/ticket) or save/validation (check if a mandatory item field is set or item field is formatted correctly). These scripts can execute just about any custom scenario that you would expect with writing code/script.