Custom domains are managed from your Site Preferences
When you remove a custom domain, either manually, by canceling your subscription or removing your account the URL's associated with that domain will display a Exposure 404 error (page not found). This will displayed until the domain is no longer pointed at Exposure.
Removing a custom domain will break any existing links shared on the internet unless manually forwarded outside of Exposure.
Changing a Custom Domain
Changing your custom domain has the same effect as removing it for links already shared. Any previously used custom domain links shared on the internet unless manually forwarded outside of Exposure will display a 404 error.
At this time Exposure can only connect one custom domain at a time.
Keeping your Exposure account but removing a custom domain
If you simply wish to stop using a custom domain then your Exposure URL (username.exposure.co) will still be assessable when sharing your site and stories.