Continuing the discussion from Submitting a payment request:
Admitted. It’s one of the things that are really hard to change in Discourse, though.
But you can cut & paste to an external, visual Markdown editor, edit there, and cut & paste back to Discourse. Since this will only be needed for a few complex wiki posts, it seems acceptable.
We’ll have to find and document the right external editor first, though. Documentation about it will appear in “Formatting and structuring your content” then.