This is definitely possible.  As the lockdown menu is defined by html/CSS/javascript rendered on the device default renderer, there are countless ways to do it, depending on the tool/framework/library to be used.  Please note that differences in Android firmware and renderer versions need to be considered if a single lockdown payload is to be assigned to multiple device brands/models. 

However, this customization is not as easy as adding lockdown menu items in the web console GUI.   It is unlikely to be straightforward for anyone without web page programming skills and technical knowledge of MobiControl lockdown menu.   Depending on your requirements and the kiosk complexity, you might need to contact Soti or local distributor for possible technical support and/or professional service.

Thank you very much for the information.