First thought

[ololololo]

I'm yet to find the exact alphabet, but there was a significant seam of Southern Germans writing in made up alphabets at the time.

Are there any examples other than runic alphabets?

I'm not sure you need to go as far as to have a mental illness to validate the script...

This is an oversimplification. It’s one thing to “write in a non‑standard alphabet,” and quite another to “write a non‑standard book.” In the case of VMS, it’s not just about the alphabet.