Size of DXF is different once imported

LightBurn assumes the new standard of 96 DPI.

You have a few options:

  1. Convert the 90 DPI files to 96 DPI prior to importing into LightBurn. I believe Inkscape may ask you how you want to convert if you load an older version file into a newer version. I’m not certain about this.
  2. Load the files directly into LightBurn. Then scale the whole design by 106.666%. This should correct for DPI change.

You can read about the DPI change here:
FAQ | Inkscape