The author also could create a new post stating that some changes have been made if it's worth an update in his opinion. I don't think any other concept is needed since editing posts is more wiki-like than forum-like. If your forum relies on something like this you might consider using a wiki platform instead or additionally.
@yariplus So I tried the "npm install nodebb-plugin-markdown@latest" and I got permanent 502 gateway error. Then, I tried deactivate > install markdown from the ACP. In the second attempt, markdown table works. In both cases I saw this.
Thanks for the help. Now I can finally have nice looking tables