Yes, but I don't know how effective it is. 99% of the time someone leaves a 'nit' the other person fixes it. So we're still dealing with most of them like regular comments. Only once or twice I've been like "nah, I like my way better" but I can only do that if they also leave an LGTM. Sometimes they do. There's one or two people that will hold your code hostage until you reply to every little nit. At that point they don't feel like nits. I always LGTM if the code is functionally correct or if the build breaks in a trivial way (that would also block them from submitting). Then they can address my nits or submit anyway and I'm cool with that.

I wonder if there's a psychological benefit though. If someone states up front that they know something is just a nitpick, the author might be less likely to push back, and therefore it's less likely to end up in a bike shedding back-and-forth.