So then what is the approach to this verse, or to verses in that style that claim something which, by everyone’s standards, is testable? That it’s a metaphor?

First you have to check the facts, and only then think about interpretations. The gates of interpretation were never locked, so it’s also not really interesting to me to deal with this.

Isn’t there some consistent interpretation? Some kind of criterion?
If everything is open to interpretation and there’s no point dealing with it, then what is relevant? What are the points that are worth dealing with when examining these things?
Because this motif of “do such-and-such and you’ll get such-and-such” is not rare at all, like the claim that honoring parents prolongs life… so are you basically saying to take all of that out of the equation?

In my opinion, yes. That’s why I keep writing that studying the Hebrew Bible (Tanakh) is one huge waste of time. I’m already tired of these empty discussions.

Rabbi Medan has a very beautiful and revolutionary interpretation of this exact verse.
You should listen to it.

The Day the Bible Was Sealed — okay, can you just be specific about the video or article where he talks about it?

I think it’s here
https://www.hatanakh.com/lessons/%D7%9E%D7%93%D7%95%D7%A2-%D7%A4%D7%A1%D7%A7%D7%94-%D7%94%D7%A0%D7%91%D7%95%D7%90%D7%94-%D7%9E%D7%99%D7%A9%D7%A8%D7%90%D7%9C