It doesn't happen all that often, but remember that under FRCP 72, a party can object to a non-dispositive order by a magistrate judge:
(a) NONDISPOSITIVE MATTERS. . . . A party may serve and file objections to the order within 14 days after being served with a copy. . . . The district judge in the case must consider timely objections and modify or set aside any part of the order that is clearly erroneous or is contrary to law.
Parties sometimes seem to forget this, because unlike with Report and Recommendations on dispositive matters, the magistrate judges do not typically flag the 14-day objections period in their orders.
And, sometimes, it works out. In 2019, for example, Judge Noreika sustained an objection to one of the magistrate judge's common interest doctrine determinations, reversing an order to compel certain common interest materials. See AgroFresh Inc. v. Essentiv LLC, No. 16-662 (MN), 2019 U.S. Dist. LEXIS 172423, at *13 (D. Del. Oct. 4, 2019).
All of that said, other times, it does not work out well. Today Judge Connolly denied such an objection before the other side had even filed a responsive brief:
There is no need for Plaintiffs to respond to the objections. . . . The Magistrate Judge's ruling cannot reasonably be characterized as clearly erroneous or contrary to law. . . . Accordingly, IT IS HEREBY ORDERED that Plaintiffs' objections (D.I. 62) are OVERRULED.
So, yes. "clearly erroneous or . . . contrary to law" is a fairly high bar, and these kinds of objections probably should be uncommon. But don't forget that it is another tool that is available when it makes sense.