If you buy an OMTech or Cloudray from the Amazon Cloudray. The main Cloudray site will not honor any warranty or service, you will have to go back to the Amazon Cloudray from whom you purchased. Same with OMTech… Ensure you read the warranty information on any site or related site.
This Snapmaker FAQ refers to it as a 1.6W IR (assumption) addition. If you haven’t, I’d suggest you read it, lots of compatibility answers.
4mm dof is great. Keep in mind the longer the dof the larger the spot size. Longer lenses have a larger spot size in exchange for longer dof. Larger the spot size the less apparent power as the same power is over a larger area.
I didn’t see any data on the actual spot size of each, but I’m sure it’s floating around somewhere on the Internet.
I don’t know of any solid state lasers that are not square of rectangular, so your lens is focusing it gets, just like a camera. If it gets a rectangular beam for an input, it will focus that same rectangular beam for an output.
I think it may be a different machine, but seems OK… Generally if it uses the normal communication mode and speak grbl, it should work with Lightburn.
As far as I can tell, they are separate modules. The 40W can do anything the 20W can do and cut deeper or thicker materials. Running the 40W at 50% power should produce the same effect as the 20W. It’s putting down the same amount of average power.
Keep in mind that some of these modules posses more or less mass than other. The link indicates the IR module compared to the 10W module, you must slow the maximum speed from 6000mm/m to 1000mm/m
Check out the link and see if I have the right modules… all of this could be moot 
It’s also helps to advise us of what you want to do… Most of the IR lasers that are not fiber types, really don’t do that great on metals. I’ve read lots of frustrated users claiming they can’t get the advertised results…
It’s nice to be able to upgrade. Pick wisely…
Good luck
