Yes, the comments in the code have been added as a note that any changes to the property values will result in element dislocation. We are using a link tag width two nested spans in order to achieve both rounded corners and ability to keep the rounded corners with different widths of the buttons. Probably, in the coments I should have had to add that the offset of the spans is equal to the corner-radius of the images that the rounded corners consists of.
The reason that certain values are hardcoded in FormDecorator.css (the base stylesheet of the control) is that we have tried to minimize the page jumping during the process of skinning. This is why we have taken the original buttons' fonts, font-sizes, weight, padding, margin, etc.
Any modifications to these properties may lead to page jumpings, element dislocation, etc.
However, if you need different settings, you have to modify the base and the skin-specific files, as well as the respective image sprites that the button consists of, but have in mind that we will not be able to handle problems that may arise. At least at this stage.
the Telerik team
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