The functionality you describe is not supported by the Kendo UI ThemeBuilder and is not planned for a future release in the near future, but I see how it could be useful.
I encourage you to participate in the Kendo UI Feedback and Feature Request Portal
in order to share your opinion; if the functionality you propose gets enough votes, developers will take notice and might implement it in future releases of ThemeBuilder. Here's a link at the related items in the portal
Thank you for your understanding.