The XNT 9 QB 90 T will work on the 898 unit to provide you with traditional down sonar and temperature. However it does not provide you with DI or SI features.
To use both the HDSI and the Quad beam transducer you would need to use the TS3, transducer switch. The Y - cable AS SI DB Y is keyed for the dual beam transducer so you would not get QUAD beam with the use of the AS SI DB Y.