Using hidden codas rather than the 0-line instrument makes it easier to align the gap in each system which passes through the text frame while continuing to have only one music frame:
Each coda to the right of the text frame uses the property Hide systemic barline to remove both the brace and barline, making it necessary to replace the barline with a vertical line. Each treble clef to the right of the text frame is replaced with the invisible clef, and each bass clef is replaced with the invisible bass clef from this post. The normal clefs are restored at the beginning of the next system, and a coda is added to hide the courtesy clefs at the end of the previous system.
Here is the revised project:
Layout Flows Around Text Frame v2.dorico (657.0 KB)