We are using both Fancy Product Designer and Multistep Product Configurator, similar to the "Shoe" example you have. We have a custom text area and would like to connect it to the MultiStep somehow, so that it would show on a mobile device and also so that this step does not get skipped. I can provide the link in a private conversation if needed.
This is not possible and can only be done in a customisation job. Currently we are not available for any custom job. But we have a partnership with an external company that offers WordPress experts from just $29 per hour. I am sure they can help you with your concern.