As I kept writing Flarum extensions that extend the parser, the need for a command that would re-parse all the past comment posts using the new formatter's configuration arose each time. I then had the idea to make yet another extension that would provide this command separately as it could be useful in many cases. I thought that this extension could maybe provide more of these "general maintenance" command, but right now I don't have that much other idea, so if you have some command in mind that you always wanted to have as a Flarum admin, I am curious to know about it, and you are of course welcome to submit a pull request 😉.
Here is my extension : https://github.com/club-1/flarum-ext-chore-commands
For now there is only one command (and by the way, I would also be interested if some of you could test it on a big test database and report the possible issues):
chore:reparse Reparse all comment posts using the latest formatter's configuration