Not Mini Schnaus, but purported/presumed APBT x Jack mixes aren’t uncommon at the city shelter I volunteer with, and I’d guess the temperament would probably be fairly similar? Both APBTs and Jacks are very common around here, so I assume most of these mixes are one-off oopsies, since it seems unlikely there’d be much of a market for pit x terrier crosses specifically. From what I’ve seen they’re usually a bit more easygoing than a pure Jack, but with just as much prey drive and a bit more tendency to be dog-aggressive. Game-bred APBTs can run pretty small; 30ish-40ish lbs. isn’t unusual here. Mini Schnaus aren’t quite as popular as they used to be–AKC top 20 now, down from top 10 in the late 20th century–although that probably varies widely by area; I seldom see them locally. I assume your dog has the wiry/bearded coat, always thought that looks cute on pit mixes.