Nah, not at all.
The current through a CO₂ laser tube determines the output optical power, more-or-less linearly proportional to the percent power setting in the LightBurn layer, so you can set the power to suit whatever you’re doing.
However, each tube has a minimum current at which it will operate, thus setting the lowest power the tube can produce. That current depends on the tube’s:
- Maximum current rating
- Temperature
- Age
There are also peculiarities involved at very low power levels, but those are common to all CO₂ lasers and their power supplies.
The lens also matters, with various focal lengths producing various spot sizes, but that’s likely secondary to a well-aligned optical path with good mechanical setup.
Basically, run a bunch of test patterns to see what the machine does; you’ll likely find it works better than the doomsayers would have you believe and you won’t run into its limitations for a long time.
Worst case, it doesn’t make exactly the thing you wanted, but it cranks out a perfect moneymaker you never expected. 