One detail about ARFs stands out after you've experienced a few.

Overall, the workers in the factories do not have much idea about what they're assembling. You will experience and hear about models that have fatal flaws in them. For example, my Tiger60 ARF came with a steel elevator connector that was cracked somewhat. I immediately tested it. I've autopsyed a number of ARFs that had stabilizer flutter. The most recent couple had adequate design but worthless balsa, wood that no experienced builder would have put into their model. Experienced kit builders would have rejected the punk wood and substituted. Experienced scratch builders wouldn't have chosen the wood for that purpose. (maybe not for any purpose) The ARF workers simply glued in what was in front of them to use.

As for the plants dilligently testing their designs, I've got to suggest that maybe some do, but don't bet the farm on it. We've seen a number of tricycle geared planes with mains that are directly under where the CG is suggested. That's actually an ignorant thing to do if you're designing. Almost everyone has lots and lots of examples of things that weren't simply assembly line QA problems.

The one thing that needs to be stressed about ARFs is that they are presently made in a manner that requires modelers to have some experience to insure their safe operation. Impossible to do? Yeah, until you've gone through enough of them to have gained some experience.

How are they made? Beautifully. But by people who would be working in a toy factory if it were a closer bicycle ride from their house.