Labels in headers reserved space for an icon even when no icon was used. This is caused by the shared function ui_text_icon_width adding 1.5x a buttons X-units width the the width of the string. Menu buttons detected this and subtracted the extra padding. Instead of adding the same workaround for labels, add ui_text_icon_width_ex that takes a padding argument. Add presets for 'default', 'compact' and 'none' to avoid duplicating padding values. This allows removal of hard-coded label scaling for the add-object tool.