As I said, the chances of actually running into problems with one's limit--be it Physical, Social, Mental or Accuracy--aren't really all that high for a well-rounded character.
If you're really concerned with defense tests getting 'auto success', just apply the Physical Limit to them*. It really should apply there anyway.
* Or, if you think that Limit will be too high for a defender, do something kind of unusual and apply that Limit to defense tests just with it being calculated only with natural (before magical, cyber or bio augments) attributes for that purpose (and that purpose only).