-In the 'Remote Address Override' text box enter 'X-Forwarded-For'
Oracle has an internal MOS support note 1531012.1 which they said they will publicize at some stage in the future... but not at the time of this writing.
Unfortunately, none of the steps above address the initial question "PeopleSoft Access Logging (PSACCESSLOG) Showing IP Address of LTM".
PSACCESSLOG is actually an internal PeopleSoft database table that gets written to when a user correctly authenticates to a database. My initial research indicates this requires custom code to get the IP being written to the weblogic PIA_access.log file but I haven't yet confirmed this. I will update if I get a decent solution.