All the OAS versions, and even OBIEE 12c, are on the same "family" of FMW versions: doing that setting for the discovery cache is part of my default install steps, I actually have that scripted just like most of others tasks.

If you happen to do a number of installs or installs all the versions every year, I find it a gain of time to script all the configurations, including those in WebLogic Admin Console (using WLST) and in FMW EM (files or WLST again). It takes me a bit longer to write the script the first time, but then it is all executed automatically (as long as the base stack is 12c, all the configs will always be the same).

Things like adding another authentication provider (AD or LDAP), enabling SSL with certificates, configuring the system to have a proxy in front etc. Of course, no need to overdo it if you don't need it often, but the EM cache discovery you can consider it a default task all the time.