I wonder how many successful law suits have been filed against shops and binding manufactures for incorrect DIN adjustment? With all the other variables involved (conditions, speed, skiers honesty in stating weight, height, and ski level ,... and jumps ... I am sure that falls out side of the companies definition of "normal use") not to mention the obvious, that people jack their din the second they leave the shop.
I am just saying, it seems unlikely that a legit lawsuit would be settled based on the on-line recommendation of one interweb douche, and another douches willingness to follow said recommendation.
Besides, I have be tweaking my own din for 15 years and have yet to have a serious issue. Lots of people tweek their din.
However, when it comes to mounting bindings ... please get it done professionally. I feel that the only way should ever mount your bindings at home is if home is a ski shop.