In the Northern Irish dialect, a speaker can say
You see, I would have been very shy, and his encouragement really helped me.
Here, the "would have been" is used to indicate that the speaker is recalling a general state of being from the past, rather than any sort of conditional. It's used as a rhetorical device to encourage the listener to imagine a situational context. An alternative rendering of the same might be "Back then, I tended to be a very shy person, and his encouragement really helped me."
Is the use of "would have" a known language device? Does it have a formal term?