Support for tour steps that have no spot (no AttachStep)

I haven't found anything in the examples or guides showing how one would include a tour step that does not have an associated AttachStep - ie. a step where the spotlight goes away and the rendered tooltip is just centered. Am I missing something or is this not available? If it's not, is it something you would like me to contribute? If it is possible with the current package, could someone point me in the right direction to implement it?