At the moment, there is no way to customize email subscription settings. The only option is a hard-coded 'Unsubscribe' button.
Instead, it would be much more helpful to have an 'Unsubscribe' button that then takes you to a screen where you can have some options about what you want to unsubscribe from. "I want to receive fewer emails." "I don't want to receive solicitations." "I only want to receive newsletters." "Unsubscribe from all communications."
It is also necessary to have the option in NXT to filter on those with the DNC code on their email because they unsubscribed. Currently pulling an email list to use outside of RE can't be done in NXT because there is no filter or column to show the Do Not Contact added to the account when they unsubscribed. It can be done in Database View, but now that solicit codes have Valid to dates that end the Do Not Email solicit codes, that is not visible in DV. I'm stuck without the features needed in either view to manage the process of pulling accurate email lists. I hope to see this filter in NXT soon. Thank you.