Well the beautiful thing about blender is that there’s more than one way to do things. For example if scaling down drawing doesn’t work for you then you can scale everything else to fit your drawing. Just move the camera further away. Another option is to convert GP to Curves before scaling down. You can convert back if you need to. I can’t remember if it’s in draw or concept course, but Paul points out a way to quickly adjust line thickness. I want to say it’s in the GP sculpt, but I don’t remember.