Not worth it.. invest in better material and cleaning
Ive got 2 lasers here in my shop, a 40 and 100w, and cut everything from .02" acrylic to 1" poplar on a regular basis. I find that most of my flareups happen from creosote / resins that build up on the bed. Clean them up, and the occurrences go down.
Speaking of, honeycomb works. Barely. Get a pin bed. Lots of plans out there for making your own. Increase air pressure when cutting, that will help too. I use up to 30PSI on some projects and materials.
One of the issues you will see with CO2 is possible thermal shock of your lens, fogging of the same, although I suppose you could use it in conjunction with running a coil through your waterbucket or near the inlet of your chiller.
But until you start cutting volatile materials, or cutting steel (and that requires much more wattage) stick to what works. Unless you really want your consumable budget to skyrocket.