Luban 3.9 and laser engraving

Some weird things I found on my first attempt with Luban 3.9 and Laser engraving:

  • Precessing, or even changing contrast or brightness, basically everything I do slows down my Ryzen 3900X as if I would render a 8K movie on my old C-64. Is that normal?

  • after processing the picture is way too dark, looks like if it’s black and white?!

Editor:
Screenshot 2020-11-01 002646

Process:
Screenshot 2020-11-01 002607

  • loading to workspace is not working, Luban flips to workspace, but nothing shows up?! I’ve checked “Preview in workspace”. After several attempts it works sometimes. Reading the manual I understand, that I should select material thickness, Auto Print Mode and laser power. I don’t see that options anywhere??