When using Rich Text tokens, the HTML code is also visible on the text version of the email and it is tedious to remove it. An HTML to Text Email Converter would be useful to "translate" HTML tokens to plain text.
I like this and have definitely discussed this internally. The issue is that we won't always get the TEXT exactly right, so we'll also need a way for users to override it. In our Snippets, for example, you can edit both the HTML and TEXT versions of the snippet. We may need to just simply add this feature for rich-text tokens. We can try to automatically create the TEXT side but let you override it.