So, just to demonstrate what is also possible with a 60Watt tube and I have not even optimized the parameters properly yet.
I mean, even though the laser beam is an additional 0.5-1mm larger, (before the lens), at an 80Watt tube, you always have the option of using a 1 or 1.5 "lens, which should provide a very fine focal point.
I also have a 5.5Watt diode laser, but besides balsa and poplar I could not use it for quite a lot without it getting too sooty and charred.
But from 15 Watt diode laser to 80Watt CO2 laser - I call it a proper jump up the ladder. If it is this kind of thing you do primarily, then a 50-60Watt will handle the task very well. It’s a difficult decision.