Seven or so years ago, over in the legacy forum, @mwra wrote about using Graphviz for exporting notes, which could be also rendered (at that time) in OmniGraffle. I did numerous experiments and have a folder of those documents that still work in Tinderbox 7.x .
Ultimately, I found it to be a dead end because the exported documents took quite a bit of care and feeding and do not at all approach the appearance and features of Tinderbox maps. It was an interesting toy but not something I found useful in using Tinderbox day to day.
I have no idea if OmniGraffle, which itself has moved into several versions past 2010, still supports Graphviz.
BTW, if you were looking at Graphviz as a way of getting a Tinderbox map to paste into another document, Edit > Copy View as Image is useful and requires no coding.