I see Finn’s arc in TFA as going from someone who learns the value of life (and thus fears losing it) to someone who will give his life for his friend. In TLJ, he goes from fighting for a single person to fighting for a noble cause.
I don’t know how much Finn wants to be seen as heroic. Obviously he wants to be valued, and at the beginning of TFA he believes that the only way to do this is to lie about himself, but that’s about it.
This has given me some more to think about for sure.