As of now though we cannot use PG for any PCI/DSS certified application because we can't enforce either complexity nor regular password changes,
You can, and many, many companies do, but you need a modern auth system like Kerberos. Even if we were to put something into Postgres today (and given the MFA and re-use requirements, it's near impossible), PCI DSS keeps evolving and getting stricter, so keeping up with it would get harder with each release.
Can I do something to help bringing these feature into PG? My C knowledge is very limited so I won't be able to provide a patch but I'd be more than happy to test it.
Your energy would be much better used in bringing Kerberos into your organization. :)
