First I must congratulate you for developing such a nice GUI for LB.
I am migrating to LB because I am getting a Macbook. I tested a photo for engraving on both; lasergrbl and LB.
I hope you can help with some initial hiccups.
I am running both the apps at 800mm/min and somehow with the same line resolution LB is slower by about 33%.
When using LB I have random space between lines on the X axis. There is a noticeable thud sound when X axis/laser shifts to the next line.
I am using a good quality DIY laser engraver hooked up with an Arduino on GRBL.