I’ve looked into those machines before. Very tempting, but I never have the spare $. Looking at the FSLaser cutter they make it seem like you need a ventilation system if you have a window or other outlet for the fumes or a filtration system. Could just be to sell people more stuff, but it makes sense at the same time. A simple vent system could be made with a bathroom exhaust fan and some dryer vent hose. Just make an acrylic or other clear plastic case and get safety glasses/goggles rated for whatever light is would put out.
I have no idea how to make all of the CO2 laser stuff work, but I’m sure someone here will figure it out. Would be cool to have the MPCNC down to a super easy quick swap system for different tool heads. I still see value in having a spindle and endmills for more 3d stuff, unless you mount 2 more axis on the CO2 laser and can move it at any angle as well.