Envelope Procedure demonstrates a fault, it demonstrates a longitudindal ridgeline, not a gable end vs. a perpendicular to ridge directivity. L/B ratio is missing from the procedure. Use with grain of rice.
Maybe post a picture to demonstrate? I've found a few typos in the "new" tables and diagrams in 7-16, but I haven't found any of the procedures to be fundamentally flawed. You have to pay attention to the restrictions and limitations, of course.
I'd be interested for you to elaborate a bit more @fugeeo. This procedure has been around for a long time, it is known that this section (and other wind sections) are often misunderstood and confusing. I believe the Part 1 envelope method load cases have gone back and forth with presenting the same information in different ways to try to address this. I can definitely get on board with those who think the entire procedure should be unified and simplified.