Yes it should get you very close to a good value.
There are two things to keep in mind. Kerf is only applied on a closed path. Some of the kerf will need to go outward, holes inward.
You say the size changes. I don’t know if you mean the overall size of the part or just the hole tab sizes…
When you cut something the laser follows the line in your artwork. With the beam in the center, 1/2 of the beam (kerf) will cut into the material. That line will be 1/2 the beam (kerf) size smaller. If you set the kerf to 1/2 the beam width, it will cut 1/2 beam width away from the artwork. The cut will be in the same place as your artworks line.
This is another thread about this… The Lightburn staff responses are probably the best examples of using and how it works.
Good luck
