One thing I’ve found useful, instead of trying to line up on a grid is to place a sheet of 1mm chipboard, somewhat larger than your workpiece, on the waste board. Use painter’s tape to hold it in position. Then, in your Lightburn frame, draw a shape around your workpiece stock. Set this to a separate layer to cut, set all the other layers to no output and cut the shape.
Then remove the cutout, keeping the frame of the chipboard in place as a holder for your workpiece, and change the layers back to output with the frame layer to no output. This works really well in holding your workpiece in position and is ALWAYS aligned.
There is 2 colours there specifically for tool usage, I’d add to your comment to do any construction lines in these just to minimise risk of accidental cuts!