I’ve known a few miniature schnauzers in my life. They have a reputation as small, yappy dogs. That is true when the doorbell rings. When hanging around the house they are very well behaved. Smart and easy to train. Not nearly as hyper as a Jack Russell.
I also have known mixed breed/mutt/rescue terrier mixes. I have always been partial to them, but that may be due to some good memories of a friend’s dog when I was a kid. They also don’t shed much, don’t usually smell bad, and some varieties may be hypoallergenic. But they need to be groomed/trimmed about once a month.