From what I can tell it seems like Tinderbox uses slashes as container separators, so this might just be a case of “don’t do that,” just like you can’t have slashes in Unix filenames. I’d be interested to hear from @eastgate if there is a work around.
This stamp fails because you haven’t declared the noteIDs variable. If you declare noteIDs, this stamp acts just like the first stamp.
This is my understanding. Slashes (and parentheses) seem to be non-escapable and thus whilst valid in names for ordinary use they cause a silent failure in most action code. in my research work, where notes are often the names of papers which include such titles, I normally save the ‘real’ name as a user attribute and use that as Display expression whilst I bowdlerise the actual note $Name to work around this limitation. It’s a practical workaround if bit of a faff to do.