I understand that a Chariot may not make a tighter turn then 1/2 its current chosen speed, but can it make a wider turn at the player’s option?

I ask because the rules regarding Out of Control Chariots state that when a right or left turn is rolled, “The Chariot will turn right (left) for the full distance of its move, at the sharpest radius possible.”

This would imply that a less sharp turn is possible when the Chariot is under the control of a driver.

What say you all?

I'd say yes, the chariot can make a wider turn, don't forget that you don't need to have every inch of movement turning, so at a speed of 10 you can move 5, then turn for 5, but the turn is at speed 10