I wonder why your body stil vibrating after it comes out of "gate"?
I had problem something like yours.
Try to make softer collision responce , how to say, do not responce fully:
softness=0..1;
b.position[0] -= radiusA*softness;
b.position[1] -= radiusB*softness;
place more two circles with soft responce on gate circles with full response, but with bigger radius...
but its very dependant on situation in game, good to see real situation in game

I wonder why your body stil vibrating after it comes out of "gate"?
I had problem something like yours.
Try to make softer collision responce , how to say, do not responce fully:
softness=0..1;
b.position[0] -= radiusA*softness;
b.position[1] -= radiusB*softness;
place more two circles with soft responce on gate circles with full response, but with bigger radius...