The available options for the concern:
1. See if the user TSO LOGON REGION size can be increased from 4MB to perhaps 6MB to see if this will provide relief.
Based on DB2 Reason Code 00E20003 the following is suggested:
System programmer response:
Increase region size. If the region size is already defined at
the maximum, consider enabling the CONTSTOR system initialization parameter.
2. Instead of executing the BIND Online execute the BIND in Batch.
3. Reduce the number of open split TSO sessions / vendor tools active within the same session which could cause a short on storage condition.