I’m afraid that will be very unlikely, Agenda isn’t a native markdown editor, it’s not its internal format. We only use markdown as a shortcut to trigger certain styles.
That makes sense. My biggest concern is links. If I paste a link in, it automatically infers what the name of the link should be displayed as. I cannot find a way to edit that name. The edit dialog just edits the actual link, not the display name.
If you indeed delete all the text it goes away. A workaround (if you want to replace the entire text) is to delete everything but the first few characters, then delete those at the end. The other, perhaps better, trick is to paste the link with the right text already prepared, using the markdown syntax for URLs, like this: [Some name for the link](PASTE YOUR URL HERE)