Good day, I contacted Zoho Support to enable the toggle switch for opt in/double opt in. They did so graciously without any headache, but it was the time it took me to understand and look for this button and dig through forums to find out how to do this.
Not 100% sure why it is a support function, but if it is to remain so I would suggest adding the toggle switch and then put a little * next to the toggle switch that says "Please contact support to enable this function.".
Saying that, if support didn't second guess my requirement then why not just allow us to use it?
Thank you,
Kyle