Wizard/Stepper in mobile app: navigation options in final review step of wizard

I have an 8-step wizard in my app and in the penultimate step, the user has to review all of the choices made in previous steps.

The user may only proceed to the final step of the wizard if the choices are confirmed. The final step is then showing a summary.

If the user is unsatisfied, the most natural continuation would be to start over with step 2 in order to adapt the selections. There is no real reason to go back just one step, so replacing the BACK button with START OVER would work, but I guess the inconsistency is not good for the user experience. However, adding an additional START OVER button to the navigation (as depicted) also feels clunky.

a) I wonder if a checkbox is indeed the best practice to prevent the user from accidentally rushing to the final step without a conscious review.

b) What is the best way to provide a shortcut to the second step in case the review unveils errors?

Edit: The wizard is used to configure an external device. Between step 6 and 7, the configuration is transmitted. Step 7 shows an overview of the configuration that is now present on the device. If it is ok, step 8 is an higher level overview summarizing the categories in which a change has been applied.

In case the user is not content with the configuration, it is not certain that the outstanding changes are those from step 2, it might as well be changes from step 3 or 4 or several. However, just going back one step would be useless, because this would only guide the user towards transmitting the flawed configuration to the device again.