Cross-posting what I wrote on my LinkedIn.
"Glad to see so many questions quietly coming in via private chat about Oracle EPM 11.2. I encourage anyone considering an on-premises upgrade in 2021 to spin up a VM now and make sure you can successfully get through RCU and the EPM Configurator. Don't wait until your project is scheduled to start in 2021.... act now while things are quiet and you still have time to troubleshoot. This will go a long way to have a successful project in 2021!
Please do NOT send any diagrams or logfiles to me unless we have non-disclosure and SOW paperwork in place."
One additional point I made in private chat concerning FDMEE problems.
If you get errors about missing SNP_* tables when starting up FDMEE, the installation media is the likely culprit. Open a SEV-2 SR with Oracle so they know about the issue.
While you wait from a response from Oracle, you could try this approach:
Create a new VM that is specifically for FDMEE. Download EPM 11.2.2.0 and do a fresh FDMEE install on that VM. Download FDMEE 11.2.2.0 as soon as you read this post, as I question the 11.2.3.0 base installation media for FDMEE/ODI and it will eventually get removed from eDelivery.
You do not need to configure or RCU because this VM will be thrown away once you get through this exercise. Then throw the latest EPM 11.2.x (11.2.3.0 as of this writing) on top of it and do a Maintenance in-place update.
Finally, zip up Oracle\Middleware\odi\ on that VM and copy it over to the troublesome FDMEE machines. Re-run the configurator and pick "Configure Database" for FDMEE. Then check your database and verify the many dozen ODI tables are now present.
Your results may vary. Back up the odi filesystem on the FDMEE machine(s) before you replace it. Keep in mind the above is a suggestion and might not have Oracle's blessing at this time.