we can all agree that airplanes do have some kind of structural limits, right?
Of course, and I think you can safely expect that a plane which is labelled as '3D acrobatic' with a recommended flying weight will hold up under stress even when doing demanding 3D maneuvres with it.
However since these are model aircraft and require some amount of DIY to get them flyable it also comes down to how well it is constructed by the pilot. Using the wrong type of glue for example to glue some essential parts could reduce the ability of the airplane to withstand stress and cause for failures.
So it is a combination of common sense, experience and not straying to far from the recommended setup in my book.