I have no experiencing with this, so forgive my input if its plain silly but often an uninitiated eye can catch things right? My thought in reading the thread is that your updating every frame right? so buffer the updates, don't take immediate feedback and apply it, average it and filter it for extremes or inputs that go against the norm, then after maybe 10 or 20 frames return the smoothed out data as an input to turn. In other words clear out the erroneous data between the feeler return and the input to the actor, I would think creating a data set of returns and finding a norm would be the best way to go about it. Find the number of frames it takes to get from the end of the feeler to obstacles and use a third of those frames, more or less, to smooth out movement. You do this with your new code checking for negative input, and adjusting interpolation, but I think you should be setting up a buffer where turns are checked against multiple inputs not just the immediate turn. You could do this before or after getting the actual turn rate.

Make your actor think more before he turns.