I agree, it may not be a serious safety matter but it is still a code violation. How much more would it be to use #1 ... it is a trivial cost to be compliant. This is bordering on the same thing we are talking about on the fluorescent thread.
Again, if the whole house is running on a 100a service, I would pass it because you will usually not be using any more on the generator than you would use on utility power.
That still might not be true if the user is shooting cords off to his neighbors.
