I have been testing gpt4-vison to analyze and summarize block/process flow diagrams. I see that text extraction is good but I am facing issues with arrows, especially the ones going right to left. Any suggestions on how to improve the accuracy?
Check out mermAId! It can generate and iterate diagrams.
It will output them as markdown. 
There is even an extension for GitHub Copilot which lets you generate them in VSCode!