Pete, those prints are awesome! You did a fantastic job calibrating it, I see. The Peachy shows so much promise, and your tower makes that even more obvious.

Feign, I am pretty much positive that the errors we see here are software based, and further, that they are partly due to Cura. When you run the calibration software, you can watch the laser draw a perfect square or other shapes. I think that proves that the software just needs to be worked on some more.