Family CONSIDERING dual citizenship- WHEN to report?

Some family are considering dual citizenship after learning we MAY be eligible.

I will NOT obtain it "automatically" if they do, I would have to submit an application specifically for myself, which I don't plan to.

We basically have to verify it transmitted generation by generation.

Obviously it will become reportable eventually, for example if my parent and/or siblings actually naturalize, but my question is at what point should I report it?

Is my family checking if my great-great grandparents or great-grandparents can be posthumously recognized as citizens reportable? (I assume not?)

I just don't want to waste the security officers time if it turns out we're not even eligible after they inquire.

EU/NATO country if it matters

Thanks