Hi,
to me it seems that the laser is a lot slower in lightburn then when using the neje software.
For example when homing or when framing.
And all above 50mm/sec doesn`t seem to make any difference.
The laser has the newest firmware, and for the settings I used the ones from: northlakeswoodwork
It appears that the machine settings file supplied in that link has fairly low max speed settings (4000mm/min=66.66mm/s)
You should go to your device settings and adjust those to your liking.
I see @Olli posted an lbset that has better values in: