Re: Limiting user profiles to 8 characters

It depends on what you are running in PASE.

If you're running software created explicitly for AIX, it may not understand userids longer than 8 characters, which may be a problem in some cases.

However, in 99% of the cases I've seen, people are using PASE for open source applications that work across all Unix & Unix-like systems (OpenSSH is one example, Python, Node.js, PHP, Java, almost everything that people run in PASE these days works everywhere.)

Since most Unix systems (including Linux) do not have the 8 character limit, you're perfectly safe.  I recommend enabling this envvar for virtually everyone.  The only exception is if you do have software written explicitly for AIX, consult the company who makes the software to be sure that it's safe.