I totally understand what you are saying. I strive for perfection, within limitations, on everything I do. I am an aircraft mechanic by trade, I accept nothing but the highest level of success in my job.
The pointer I used is exactly the same width of the degree markings, if you are not looking at it perfectly straight when you take the reading you will see the side of the pointer and not just the front, so you know you are not reading it correctly. Looking straight on you will just see the front and no sides of the pointer, make sense?
For me, it was the best that could be done at the present time. I am sure I will improve my technique on the next one, I will look over your thread again and see how I can use it to improve, multiple ideas are always better than just one idea as long as they are looked at in an unbiased manner.
Sighting down the wire is the key. The old pros probably just take for granted but anybody doing this for the first time would not realize .