BC7 Steering centric stability

As I mentioned yesterday, very small discrepancy on Thrust Angle in BC7 SUBARU Legacy LSi US model was adjusted into Zero Thrust condition, that correction was to the point! Wondering phenomena at the moment of starting and stopping at a signal certainly disappeared and the feeling of centricity in my sixth sense and my car duplicates together with. As a matter of fact, even a very slight discrepancy on Thrust Angle does affect on the steering response and spoils good riding taste.

Front
Camber    - 30 min
Caster      180 min
Toe-in    1,000 mm(tire)

Rear
Camber    - 60 min
Toe-in    1,120 mm(tire)
Thrust    0,000 min

Above mentioned wheel alignment datum does not show any strange phenomena, but actually feel I some lack of frontal caster angle, as fulfilled fuel tank condition still shows the lack of steering stability, more 60-90 minutes in addition of caster angle should far improve the stability while straight running phase.
Bear in mind that the centric stability and straightness in  running condition are different matters each other here. This might be why very few first generation SUBARU Legacy are still now alive 23 years later from the production. In addition, 4 wheel driving system itself might be a reason for loosening the stability, my Legacy has some special wiring to earth the rear transfer clutch activation solenoid, so it can go in the both driving condition frontal driving only and 4 WD by switching the solenoid valve while driving at any time I want, far stable condition is obtained while 2 driving condition? This opinion is just dictated after the establishment of some critical wheel alignment and axle constructive geometry.
As I am keeping E-BLE Legacy 3L model also, the 3 dimensional layout of moving parts in knuckle designing must be checked, because there must be any re-designing or change, knuckle ball joint center, steering tie rod end center and antero-posterior positioning of knuckle it self. SAI value must be different from first generation's one.