Picky about Thrust & Toe-in

Once Zero Thrust is established in a vehicle, driving feel changes dramatically, this is difficult to explain how it is. Just I say that I will loose any hope to drive any high performance car if the wheel alignment of it was not firmly set up.
I could not understand and imagine what Zero Thrust means until I came across with an article by Mr. Hajime Date who is an enthusiastic automobile mechanic in Nagoya.
He published a book "Wheel Alignment Practice" and I visited him and I asked him to adjust my SUBARU Legacy LSi US model with left steering and 2.2 L Boxer motor. I was moved so much at that time and he gave me some motivation to continue this technology till now.
Though he was one of an Agent of US Alignment Tester company, I made up my own devices for the purpose. One is the Level measuring device with LASER pointer for horizontal direction and another is a mechanical pendulum one with 1719.75 mm radius for camber scaling with reading 2 minutes per 1 mm movement at the reading position. They are primitive construction but the purposes are carried out out precisely enough to clear the precision.
Rear toe value should be Zero as one standard one, on the other hand, there exists another requirement such as the relation with the negative camber and pulling action while turning phase at various speeds. Also, rear total toe contributes the stability while straight running. As we know, mobility and stability are at odds at all.
Too much Toe-in application at rear wheel position produces unacceptable muddy, sticky and dull feeling though stability increases.
If Zero Toe-in is applied with Zero side slip condition, mobility increases loosing stability.
According to my experiences with several adjustments, 6 minutes Toe-in is the most balanced value for an ordinary passenger's car except some extraordinary sport models. It is said that the equability with the camber-pull phenomena is concerned.