I'm trying some of the diagrams in elk and it seems to break the logical flow.

You can try it with Line9's first chart: https://mermaid.ai/live/edit#pako:eNpVVEtv2zAM_iuCTilgB1mbxq...

While it's nice and compact, it actually is rougher to grep.

This is super interesting, but apparently neither Obsidian nor Typora include support for it. I guess it's actually provided by an optional plugin.

https://mermaid.ai/live/edit#pako:eNplUlFPwjAQ_ivNPW9EkMHWB4...

Mermaid does indeed provide alternative layout engines. Please do try ELK before Line9. My experience is 1) hand-tuning the layout of Mermaid, having to try alternative engines or parameters, is not what I want. I just want a graph that I can use straight away. 2) ELK more often than not does give a clearer flowchart that I might be satisfied with for personal use but I still wasn't happy putting it in a presentation in front of others.