I found it not very useful. Sometimes you will query without indexes. Sometimes it just doesn't matter. Sometimes it's a table with 2 rows and you don't want an index.

In practice I don't want to know when it happens. I want an error to be raised instead so the database doesn't suddenly die.

So the problem is (1) it's too noisy and (2) it doesn't actually disrupt the query.

Simultaneously too much and not enough.