Why bother trying to crack the remaps when you can just use an interceptor like XEDE or Procede
These have the benefits of working side by side with the ecu so you can remove it (and add it back) relatively simply and at will..... just what u need when u take the car in for service. Personally, I wish BMW would offer something for the 335 engine (whether a remap or an interceptor), I'm not sure we can expect it soon though.... here's hoping.