Wait!? You’ve been running a NNF forum for six months and haven’t told me!? Can I see it!?
Because the text -> HTML conversion is one way, there will never be an edit command because I wouldn’t be able to turn the HTML back to the markup it came from in a reliable / sane manner and that would be over-engineering anyway.
I am planning to add the ability to append to existing posts. This should solve most requirements whilst keeping the engineering down.
Since you’ve been running a forum you should have some experience with the general design, please consider filing bugs and requests on GitHub: github.com/… Doing so makes me work on it. You can thank all this recent activity on Jonhoo for commenting and filing bugs like a man possessed.