my 2 cents as i'm passing by.

We had bad surprises with plan_table synonym in 11g/12c SPM. In some cases baselines were not shown in the notes, causing many headscratches.

here is the queries template I use now:
[quote]explain plan into sys.plan_table$ for
SELECT * FROM DUAL;

select *
from table(dbms_xplan.display(table_name => 'sys.plan_table$', format => 'ADVANCED +peeked_binds ALLSTATS LAST' ));[/quote]

note: generally i remove the "allstats last" format, and if you don't want to many stuff, replace "ADVANCED" by "ALL".

hope this help