I don't know what versions you are using, but I do know that with CREO 2 and Windchill 10.1 if I try to login as a different user it throws a warning that says:
Warning: Active user changed
The server cache is registered to orgadmin.
Continuing as <user name> is not recommended.
Abort Ignore
Hopefully you can find your answer. I'll just keep on using my two shortcuts.