I apologize if I didn't explain it right. I'll use a code example:
Local $idExit = _RGUI_RoundButton("Exit", 0xB0B0B0, 10, 430, 80, 30, 0X404040, 0X404040, 6)
Here is what I am referring to:
Local $idExit = _RGUI_RoundButton("Exit", 0xB0B0B0, 10, 430, -1, -1, 0X404040, 0X404040, 6)
My intended suggestion was to be able to put -1 for the $iWidth, $iHeight sizes. For the regular button and label GuiCreate* options that would autosize the control based on the text and (as you stated) the font size. But if I do -1 like above, it doesn't work.