Is It Possible To Force A More Concise Node Layout?

As I am considering to use Mermaid to create diagrams for my thesis, I am looking into ways to make the diagrams more concise. I am not entirely sure whether that would look good, but I thought about using a smaller box padding i.e. distance between box lines and text.

Any ideas how one might be able to do that? Other ideas how we can make this less space consuming?