You sit at the back for three major reasons.

You can see the rig

You are better protected from the weather and bumpy ride

Because that is where the steering gear is usually mounted

On a power boat you tend to sit further forward because you can see where you are going better and do not need to see the rig

Getting used to it takes a few minutes

On a proa it would make sense to sit in the middle to windward of the rig with a single wheel between seats facing opposite direction. You put the top of the wheel to leeward, the linked rudders turn the boat to leeward. Opposite to turn upwind. Rudders turn in opposite rotation. You sit on the seat facing the direction you are sailing. That’s the theory. In practice it may not be as simple, and will probably take some tweaking to get acceptable balance. The rudder balance could be problematic as centre of lift will be in front of axis of rotation both shunts. Continuously rotatable rudders could solve that, but would need a chain or geared drive. Lots of room for experiment.

Cheers, Peter