Quote Originally Posted by pa24-180 View Post
If that is most cases, then in what kind of cases would one expect that the airworthiness certificate would not have that clause?
If the OL's were written in a year when FAA Order 8130.2<Rev letter> had different wording in it. Some years, it had other rules. Right now, it says approximately what I stated, and I'd expect that to be the same in the future, but there are no guarantees.

Quote Originally Posted by pa24-180 View Post
Or is it the case that almost every AWC would have that clause except for very very rare circumstances?
All of them written for EAB aircraft in the past 15 - 20 years say that, _IF_ the examiner (FAA or DAR) was paying attention to the order from which they were supposed to get the OL's. As with FSDO's, where each is their own fiefdom which seems to interpret FAA rules in their own way, examiners interpret the order in their own way.

In the words of Ralph Waldo Emerson: "A foolish consistency is the hobgoblin of small minds".

Don't sweat the issue. If you build an airplane that's reasonable to use for IFR/IMC flight, you'll be able to make it legal to do so. It's not a big deal.