In our E1 (9.1/AS400) system, there are four E1 Subsystem (1st one is E1Subsystem and rest of them(three) are timeZone specific E1subsystem)exists in Production .
Built update package with one custom BSFN along with other OL objects . But deployment is failing on three timeZone specific E1Subsystems) and deployment successful on 1st E1Subsystem.

If we excluded custome BSFN from build then deployment is successful on all four E1subsystem.

Regards,
John