I don't want to get too excited, but after some trial and error, I think I finally found the right program...
At first I changed the registry settings (as described in the link you provided above) with Resco, and that worked awesome - until the MS Exchange server re-forced the policies and overrode the changed registry settings
Turns out I needed
this program (also found via the link above) to *block* the exchange server's security policy-push. It's called "Stay Unlock" and is genius. So far it seems to be an effective goalie, running in the background and only flashing across the top banner infrequently when blocking the pushed policy.
So I'm back to simple pin every 24hrs - no more strong alphanumeric every 15mins!! I hope this sticks. If you don't hear from me again on this, it did!