On the topic of these consent flows, here you can see an approved GDPR-compliant flow. It’s not worth it. It’s impossible to make a good experience out of gaining consent for collecting people’s personal data. It’s too risky and expensive to build a business model from it.
https://techcrunch.com/2018/12/13/this-early-gdpr-adtech-strike-puts-the-spotlight-on-consent/