* Until VERY recently one rarely saw a professed Catholic dogmatically assert his private opinion against the established orthodox exegesis which is that Jonas is history not metaphor.
I think it a case some engage in reverse-Darwinin eisegesis
Sinkspur, what is the name of the exegete who taught you your ideas about Jonas and when did he write and what was the name of his book/s?
But the facts are mentioned to suit the purpose of the writer. And his purpose was to show that the God of Israel was active, that He would command an unwilling Jewish prophet to go to pagans and preach repentance, and that he would withhold punishment of those pagans if they did repent and turn away from their own gods.
And certainly the writer was inspired to show Jonah as a type of Christ: three days in a whale's belly (Christ three days in the tomb), a mission to non-Jews (Christ's salvific death and resurrection for all men, not limited to Jews).
Is that "too free" an interpretation of Jonah? Are Tobit, or Judith, or Esther historical books, or are they free compositions with some historical facts thrown in for interest?
In exegetical terms, Jonah is known as para-historical midrash.