How do I manage automatic subscription behavior?

I’m going to assume you’re still abiding by the “no machine generated content” rule

Yes, this manually compiled data, nothing machine generated.

You can’t prevent the subscription, but you can use the API to unsubscribe from each observation as you go (similar to what the third party metadata extension does).

Ah, that sounds like what I need! Any chance you can point me to the code that does that or the API endpoint that handles it?