I'm fortunate to live in a climate that's agreeable for painting outdoors. I set up some plastic screens on one side of my patio and have at it. There is lots of venting and airflow. When shooting the clear when my head may be in the overspray, I hold my breath and get in there and spray fast and then I back off. I use a charcoal mask, not a fresh air setup. I've spent some time in automotive paint shops and have seen them shoot small panel repairs using just a charcoal mask on their downdraft primer area. I questioned this and they said it meets their safety requirements. Anyway, as just an occasional user this is what I do. I don't recommend this for anyone else of course, just sharing a data point and my reasoning.