In a perfect world, the wedge wouldn't need to shrink... (drawing a fixed circle around the wedge, you'd see that it gets sucked in a bit and then finishes up at the proper distance from center.)
For now, I counter with a small, simultaneous, scaling tween.
Much like with morphSVG, adjusting the wedge shape repeatedly in ~20deg chunks avoids the undesirable behavior.
What would be the best way to chain, say, 7 calls to change the d attribute? No "trick" is there?