Graphviz (dot) or Mermaid formatting

I’m was using Graphviz, then switched to Mermaid (after blowing an hour to OmniGraffle).
Anyone know of a way to change the default layout strategy?
I’m working on a process/data flow diagram, and would like the steps to be aligned horizontally (that is, in a straight vertical column), with notes and parameter bubbles at the sides, with connecting lines.

I have everything but the vertical alignment. Both Graphviz and Mermaid want to spread the charts out, and they wind up being meandering trails.

I’m not entirely sure, but have you tried tweaking these configuration settings, often times these things want to do stuff automatically so it’s a pain to err from the norm.