Max CO2 tube wattage still useable for engraving

Hey all.

As I understand it (and that’s a very generous assumption) co2 laser tubes have a minimum power requirement for firing. So arbitrarily making something up, a 120w tube firing at minimum power might be the equivalent of a 40w tube firing on max power.

I don’t have any specific cutting requirements, but I have specific engraving use cases which include at minimum, engraving logos on wooden keychains.

So what would be the maximum tube wattage that can engrave on softwood while still maximizing cutting potential?

Assuming v-wheels for motion on a 12x24 aluminum v slot at 300mm/s as speed will be a consideration.

I have attached an example of the type of logos to be engraved.

I do not have any CO2 tube or friends with so I didn’t have any way to test.

I’ve attached pictures of the engraving work I will need to do.