I usually run my table for an hour or two (sometimes three or four on & off) at the front of my garage with the door open so there’s lots of ventilation. I also have the water table which helps to catch a lot of the dust and fumes. So I use a Miller half-mask that my son recommended from when he was welding. It’s $25 on Amazon and has two replaceable filters. It’s got a low profile design so if you wear a face shield it will fit under.
I didn’t go with anything more extreme because unlike manual cutters or welders, we’re not sitting there with our faces inches from the burning metal. I tend to be walking around the table watching it cut so I can grab a tip-up if needed so I’m getting plenty of airflow and I’m not really in the path of dust/fumes, especially with the water table.