Just a quick update; I am now finally able to make exposures with the new nmigen gateware.

There are a lot of improvements in the new tool chain with respect to ldgraphy on the beaglebone.
 - Slicing can be done on the Raspberry.
 - Motion can be done with acceleration/jerk profiles
 - Steps per scanline can be altered and is not fixed
 - Whole code base is one language; Python
 - It is much easier to align the optics; 

the design of the laser head is improved and
there are algorithms to fix the alignment and calculate; spotsize and cross scan error

I will make a video for the complete process soon.