Good to see you've added support for that but the cynic in me can't help wondering if that ANSI code is even needed. While you're right that unicode makes it easy to support, it's also even easier to output the Fraktur characters directly from the CLI application and do away with that particular escape code entirely. The bonus in doing that is you then support more terminals in the process since unicode is more widely supported than the Fraktur escape sequence.
This isn't me being critical in what you've done though. More of an adjacent commentary about the state of ANSI escape sequences.