Right. So the construct in the original post (just the start clause) won’t match the start/end pattern, and will be treated as a command, which will not execute because it’s not a command (i.e. it’s a start clause containing a command).
Oh gosh, Mark, I was dead wrong in my assessment when I said “That should work without issues as far as I know.” It is not legal to only have the start block without the end block, just as the wiki page says it’s not legal.
I’m sorry that my probable haste (or dirty ) led me to give false assurance, contrary to the correct documentation of the wiki page.
It actually looks like a standalone start clause (without end clause) could be added pretty easily, which would eliminate the issue the OP experienced (although it looks like a warning would’ve been logged when the command failed to execute).