Accessing a file hoster’s service without authorization violates the Computer Fraud and Abuse Act (CFAA) in the US and similar laws in the EU. Account sharing is against the terms of service. While prosecutions are rare for end-users, hosters do suspend IP addresses.
Add each as a separate account. JD2 will automatically prioritize which account to use for a given file hoster.
Export your account list (encrypted) as a .org.jdownloader.settings.AccountSettings.accounts.json file. This becomes your personal premium database.