Thank you for writing.
The behavior you are observing follows closely the MS guidelines for the new Ribbon UI. I am not sure whether you have tried the following properties, but go ahead and do so: MaxColumns, MaxRows, MaxDropDownColumn
. Hopefully, they will help you achieve what you are after.
In case you still have questions, please write us back with some screenshots of the behavior you are after (note that our Forums do not support attachments yet, so you will have to do it in a support ticket). We will do our best to help.
All the best,
the Telerik team