The text on the wiki page, as it presently is, says
To add an account to Miranda NG you need to have an existing account in another DeltaChat client and add Miranda NG as another device using the QR code.
from https://wiki.miranda-ng.org/index.php?title=Plugin:DeltaChatThis made me think that is something you can do. So, if I'm using an old-style E-mail relay account does that work with the plugin currently? The page has essentially no information. Maybe, the page could be revised by someone who knows about the plugin to include more details.