You are already able to drag-drop buildsteps to change the ordering. It would be very useful if you could also drag an existing buildstep into a conditional buildstep (either single or multiple).

As an alternative if that's not possible then allow a copy mechanism to copy an existing buildstep that could then be deleted (though this would make it hard to remove buildsteps from the conditional wrapper, so may need an 'unwrap' facility that copies the wrapped step into the main list of buildsteps)

I'd imagine this would be supported by default if the behaviour is implemented, but dragging between conditional wrappers would also be nice to have.