You’re absolutely right. I always have several open notes, so I never feel the friction and I forget about that limitation. It would be great to find a way around it.
Maybe find a way to remove the newly created note as soon as it appears. Or we could create a plugin that tricks Templater into thinking there’s an open note – maybe an invisible note that would become active only when all other notes are closed. But I agree that it’s not very satisfying.