Set Client Automation Settings. Either value or default is required. Supported settings to change:
DefaultPaymentModule - set default payment gateway to module ID for future and existing services
CreditAutoApply - set to on to auto-apply client credit, off to disable,
GenerateSeparateInvoices - control invoice merge settings. Set to off to NOT merge invoices, due to merge those with same due dates, or on to merge all issued on same day