We install our software on one plex and then distribute the executables to the run time plex. As part of the install script (ENWSIns.sh), it validates that the port is available and if it isn't the install fails.
Two things are an issue here
1) The port might be available on the runtime sysplex but not the installed sysplex.
2) Site is using TCP/IP binding. Even if this were being installed runtime sysplex, the port would not be on the LPAR that TSO runs on, it would be an IP address allocated to the plex IP stack.
Know problem P7313. Resolved by ptf RO87871 .
Check with support.ca.com for published ptf.