Abstract;
 I made progress on some points but the laser scanning error is still too high
 for exposure.
In long: 

 I merged the FPGA code to control the prism motor with the rest of the laser head FPGA code.
 The number of LUT required for my design decreased, due to improvements in the tool chain from
 Yosys HQ.
 Previously, I increased the coil size but had not increased the magnet size. When I increased the magnet size
 It became more apparent that I had issues with the Hall sensors. They would jump back states.
 The cycle became (CYAN --> RED --> CYAN --> RED --> YELLOW --> RED --> YELLOW --> GREEN etc).
 I tried to fix this with the software (failed), then tried stronger sensors (failed) and now moved them away from the center
 (improvement, not completely solved / see picture) probably right direction.

The mechanical design also changed.

The core idea here is that only the prism rotates and the rest is fixed. As the prism is assumed perfect
 Cross scan error is low. So far I found out that the prism can still vibrate vertically, as it is unconstrained.
 
A further complexity arose that I tried to fix my mechanical design while I was still having issues with the electrical design.
Long story short, it is improving but more challenging than hoped.