I would like to be able to generate white space between buttons. At present we cannot do this. It seemed as though the divider would be the tool for the job, but it's behaviour is odd.
It would also be nice to set internal padding for button bars. If we set top, left, bottom, right to 4,2,4,2 and created a border for the button bar the outer frame would be 4 from the top and bottom and 2 from the left and right. It would be necessary to set an internal padding of top, left, bottom, right to x, x+2, x, x+2 to compensate.