File > Export DDL File brings up the dialogue which (in my case) defaults to Oracle Database 12c. I want to change the default to Oracle Database 12cR2. How do I do that?
After changing the option to "Oracle Database 12cR2", it defaults back to "Oracle Database 12c" the next time I run the DDL generator.
One may expect that the default is taken from here:

That appears not to be the case.
: