I think this idea is great!
But I can well imagine that for this not necessarily a new ID must be introduced. For example, each note could already be a template, which is used as it is. If special fields like "{{date}}" appear in this note, they will be treated special and filled in accordingly.
I already have three computers and my cell phone equipped with joplin, which works fine; but I see that with templates I have to synchronize extra between the three computers. Since this is too stressful for me, I have created a notebook for templates. Here are all "template notes" contained, which I only just copy to the relevant place where I need them. Afterwards I fill in all the special fields by myself.