It would be nice to allow multiline BINDs. I'd much rather write this than put it all on one line:
#+BIND: va/org-dot-preamble "digraph g { #+BIND: rankdir=LR nodesep=0.2 ranksep=0.1 arrowsize=0.2 #+BIND: node [fontname=courier fontsize=8 margin='0.02,0.01' shape=circle width=0.1 height=0.1 label=''] #+BIND: edge [fontname=courier fontsize=8 labelfontname=courier labelfontsize=8]" The usual continuation syntax of backslash before the EOL can be used. Or else, a new keyword #+BIND1: for each continuation line. The function to fix is ox.el::org-export--list-bound-variables