Depends on what you are doing for sure. Many people build enclosures, add air assist, fans, venting tubing, etc. depends on skill level, desires, knowledge, etc. some don’t care, don’t vent. Some use in garages, use a fan, etc. Even with cost of adding those things, you are still well below the coat of the much bigger and more expensive lasers. one thing you want to be careful with is knowing what material you are burning as some can be quite toxic. This is true no matter what laser or setup you use. Some things should not be burnt, some things can be burnt if handled properly with enclosures and proper venting, educating yourself and making sure of proper setup is the most important thing you can do.
I have used mine next to open French doors with a fan when I first got it. I was hesitant to do it, but was doing small test burns on wood so went ahead. That was before winter and weather was good. Worked fine. Even when hubby came home, he could not smell any smoke in house. When winter came more prominently I moved it out to the garage. I have used with garage door partially opened and closed (depending on the weather. ) With fan blowing across, clearly smoke smell more noticeable if garage door completely closed but has never set off the smoke detectors (in house or garage. )
one day I will have hubby build an enclosure for it probably with vent if I want to move it inside but since I don’t burn a lot with it, or big projects doing it this way works.