Also known as code switching. Many people do this all the time in the real world. I know black folk who have two distinct accents depending on the context and audience. Same with many southerners that I know. The drawl becomes a lot less pronounced in "professional" settings. That being said, V didn't grow up with Jackie. They met on a run. Corpo V might have grown up on the street as well, but then it's not really a different backstory.