A little error grows when it’s proportional to the size!
That will work, but you can also apply an offset to the entire layer.
Negative values are “inward” and positive values are “outward” relative to the nominal perimeter.
The gotcha: layer offsets apply to closed shapes and can have peculiar interactions with complex patterns. You may not want to apply an offset to everything in the layer, which means you must move those shapes to a different layer.
With that in mind, I apply offsets to specific shapes needing a precise fit, so I can verify what’s about to happen.
The kerf width depends critically on the material, speed, power, and perhaps the moon phase.
A handy pattern / tool to measure the actual kerf in whatever you’re cutting will come in handy:
Think thrice, measure twice, cut once!