I have a 3 step form, with 1 question in each step and only a yes/no option for each question.
If the user answers NO to any of the questions, even on question #1, I want to show them a sign up page ONLY at the end of the form so the user will need to go through the rest of the questions.
You will keep a single custom state called show sign up of type yes/no with default no. All the NO buttons will have a workflow to change this custom state to yes. And at the end, you will just show or redirect to sign up page if this custom state is yes.