Q. When I want to cancel this service and contract for a service of another company, will I need to disable DNSSEC before I cancel this service?
Yes. You will need to disable DNSSEC. Similarly, when you cancel another company's service and sign up for this service, you need to disable it for the service in advance.
If you are using this service and the Domain Management Service, refer to "DNSSEC Management" for how to configure DNSSEC settings.