I can understand the apprehension, as it's entrusted to them they carry the can.
As said there are other people who can set these ecu's up.
A off the shelf chip can never really, unless by pure luck, be as good as a mapping session, that is tailored to your car only, msd will use thier experience of all things cossie to get you a ace chip, though thinking sensibly it would if anything have to err on the safety side.
tabetha