Hi,
Thanks for your interest in Syncfusion products,
Refer the documentation at the following link for the information on ComboBoxAdv height settings.
http://help.syncfusion.com/ug_83/User%20Interface/Windows%20Forms/Tools/default.htm?turl=Documents/customizablecomboboxadvheight.htmPlease let us know if you need further assistance.
Regards
Vallarasu S.
Note: this feature is included in our Volume 3 release Essential Studio - 8.3.0.21