Actually if Scholz's star had a planetary system, that would not make any meaningful difference for the larger numbers especially considering the low accuracy. E.g. using your thought, it might take 109 years instead of 110 to reach a planet orbiting Scholz's star using a nuclear engine. So the distance would not necessarily be a lot smaller. It does have a brown dwarf companion, but again it would not make much difference time wise. Being discovered in 2013, it is not known if it has any planets orbiting it. Another question is if it gravitationally captured anything in the Ort cloud.
According to the article, there will be a satellite launched that will be able to provide more information on stars passing close by both in the past and in the future.