I ordered all the parts to build the PCB. I am using the parts from the BOM but I ordered BNO085 instead of MMA 8453. I am still waiting for the parts to arrive so I am trying to read as many posts as possible to get familiar with building the PCB. I am using the board to steer the tractor only, I am not using a section control or anything else at the moment. I have three questions for now that I can not find an answer for:
1- What Arduino files do I need to use for the board? There are many folders in the support folder for the PCB.
2- Should I assemble the board first and then load the settings to the Arduino Nano or load the settings and then assemble the board?
3- There is a discussion about AOG without WAS and it shows some promising results but it still needs some work as mentioned in this post:
AOG without wheel angle sensor - #40 by GoRoNb
Are there any updates on this topic? Has anybody tried using it other than @Alan.Webb?
Thank you all for your help. Looking forward to getting the PCB and having fun assembling it as you all mentioned 
.