I don’t think the goal was to make a bullet-proof delimiter that fails at nothing.
The goal was to solve the problem of not allowing things like commas, quotes, newlines, tabs, pipes, etc. in text files.
I feel like using the proposed ASCII characters would eliminate these limitations, while also allowing machine creatable and readable format (emphasis on machine as opposed to human).
Yes, it would still be tough for a human to type or read these delimiters, so in that case, go with traditional CSV or TSV (or MVCSV!).
But if you only need to use a machine to create/read the text, this sounds like a great solution, allowing all of the normal characters you might see in text.