What is your understanding of it figuratively?

I understand it as phenomenological language.  That means it describes the appearance of a thing without meaning that is the reality of it. For example, many people speak of the sun rising, even though they think the earth moves around the sun, because it looks like the sun is moving.

When Scripture speaks of a firmament it is talking about what the sky looks like rather than its actual nature.

Too many Catholic scholars and Fathers say otherwise.  But then, you permit yourself the luxury of interpretation of Scripture, but Fathers and the Church not so much.  

Or, they were right and you are wrong

You believe that the clouds are above the stars? I ask this, because Scripture says that God placed the sun and moon and stars in the firmament of heaven, to shine upon the earth. The firmament cannot therefore be clouds. We can easily see that the stars are above the clouds.

Some scholars who interpret "firmament" as phenomenological language say it refers to mist or clouds.  Another phenomenological interpretation is that the sky is a similar colour to water, so "water above the firmament" refers to the appearance of the sky as blue.

I am someone following Church teaching.  Teaching which says the Fathers are giving their personal fallible opinions.  Teaching which says that this is the way Catholics ought to interpret it.

I am not deciding what Scripture says. You are the one doing that.  Why can't you understand that it does not matter what some Fathers said?

I am saying it because the Church has encouraged me to say it. I did not come up with this on my own.