Although I know people are doing this in GT for reason, I cant replicate it to the point where I see to make any improvements.
But then again, I dont know what
exactly needs to be done to make the most (anything) out of this unique
technique.
Coming into how realistic it is: null, physics dont care for the number on the selected gear, the only thing physics care about is friction between rubber and ground, air and body, and the vector the body is moving with be that accleration or braking.
Just changing the gear doesnt change any other variable as long as the intended speed is the same .
If you can take the angle at speed x in 1st, you can also do it in 2nd, though GT wants to tell you it wouldnt be possible or slower