IEFTMS22 ENTER PASSWORD FOR usermod or REPLY.... does support a mixed case password.
When you start TMSINIT to bring in new options, to batch active or deactivate CA 1 you may receive the IEFTMS22 message which you will need to reply to with your password. CA 1 now supports entering the password in mixed case, not just upper case. If your userid password is mixed case you will need to reply to the IEFTMS22 message with: REPLY xx,'Password'. The password needs to be in single quotes in the reply.