We have just released a preview version of some of the design-time improvements.
Add Bootstrap rows and columns
In previous versions of Radzen Bootstrap rows and columns were created automatically when the developer dropped a component onto the design surface. Now you can add rows and columns from the toolbox. You can also specify breakpoint sizes of a column as well as column alignment inside a row.
You can now resize components freely or specify pixel or percentage size.
Padding, margin and more
This version allows you to specify padding, margin and other CSS attributes.
The developer can now rearrange components via drag-and-drop in design mode.
You can grab the preview release from here: