Getting the handle/grip/hand/arm up inline with the shaft is important, but I disagree about it being %80 of the accuracy. Most of the accuracy comes from correctly configured stock, bands and shaft.
The point I made which you took issue with has no direct correlation to accuracy, I just meant that you can only shoot the gun holding/gripping it in one way with this contoured handle. The simplest example to understand it is if you were to pass this gun to a dive partner to use for some reason, and he was a lefty, it would be difficult for him to shoot. Actually the pictured handle looks left handed so my example would be vice versa. But whatever floats your boat..
Yes ,its not possible if right hand to left hand, I got the point