I have a theory about this auto-exchange and I would like to see your opinion about this.
I was under the impression no matter what coin you mine or exchange to, it's going to cost you .1% fee. Is this theory not correct?
0.2% not 0.1%, but that's a different story. This fee is payable to the pool admin for this service. The op is talking about the losses on exchange itself.
Actually here is another benefit of using autoexchange. If you were to exchange your coins yourself you would have to pay TX fees (for sending crypto to the exchange and back) which may be larger than 0.2% that you pay to MPH for autoexchange.