Very cool to see this as a beta feature, finally :)
Button color/class and new section heading
I'd like to propose two new functions to Extension:InputBox. The first is a button color/class option. E.g. green button could be managed by "buttoncolor=green" or by 'buttonclass=mw-ui-progressive". The second is the level of the new section heading. E.g. 3rd heading could be managed by "headinglevel=3" What do you think? Could they be added?