Q: “With FWD in a slow corner, is some rotation a good way to solve inside wheelspin on exit?”
A: The simple answer is yes.
The reason this works is that you can begin to unwind or straighten the steering wheel sooner, which reduces the load transfer off the inside tire, keeping it more loaded onto the track. If you have a lot of inside wheelspin, the goal is to spend less time cornering, and therefore less time with that inside tire unloaded. The way you do that is exactly as you suggest, by getting the car to rotate earlier and the steering back to as straight ahead as you can again as soon as possible.
To me, one of the most fun things about driving FWD cars is “playing” with the timing and amount of rotation: get it just right, and magic happens as you carry good entry speed, and still get a strong exit out of the corner.
I love to left foot brake my CRX or VW in corners where changing gears is not a priority. With some throttle still on, the brakes are a negative accelerator. The rear tires in slowing take on a different slip angle. The result is the car exits very quickly.