Not as far as I know. Practically speaking there are several disadvantages–the slots limit the light on the markings, parallax effects can mess with the reading, it requires two full surfaces sliding against each other which increases friction, etc. Plus with a regular vernier scale you can see both sides of a line, which could give you a better sense of how they line up (“vernier acuity”). But in a case like this, where precision isn’t a top priority and ease of use might outrank it, I think there’s an argument to be made for it.