Is it possible to change a form type in Dynamics CRM from: "Main - Interactive Experience" into "Main"? If it is, how to change it?
Simply impossible. Interactive service hub specific forms are not interchangeable with CRM web forms or mobile forms.
These forms are only for use in the interactive service hub. You can’t use these in the Microsoft Dynamics 365 web application, Microsoft Dynamics 365 for Outlook and Microsoft Dynamics 365 for tablets.