The forehand drive from the back corner should be approached differently to the same shot in the backhand corner. I would also say this particular movement has evolved over the last 20 years.
I specifically want to look at a forehand drive where the ball has bounced before the back wall, then hits the back wall and sits up for you to strike your shot.
The old squash textbooks would say to always approach in an arch movement pattern and to play the shot leading with your front leg forward. I would say this is often still the case when playing a backhand drive from the back corner, but very rarely, if ever the case on the forehand. When you watch top players they always have a slightly more direct movement to the back corner, getting both feet closer to the ball that they usually would on the backhand side. They adopt what looks like a ‘toilet seat’ position, and strike the ball level with the very centre of their body (whereas when they lead with their front leg on the backhand they will strike the ball level with their front leg, so at the front of their body).
Looking at these photos you can clearly see the ‘toilet seat’ position. It is extremely balanced and offers a nice side-on position.