P.S. I see it's *still* dropping the space between prefix and title, and it's dropping the suffix. So it fails to distinguish the files because it failt to include the info that I've adde4d to distinguish them.
I went over the explanation of the template syntax, but I guess I misinterpreted it...
The explanation here implies that Calibre will include any spaces in the original template, but practice shows Calibre will drop the spaces, which is why I've used the weird pipe stuff to add the spaces, and found it still drops the spaces.
https://manual.calibre-ebook.com/template_lang.html