My guess is that some of the issues may become more prevalent… I also suspect that there is an element of required training; learning to hear the distortion.
I’ve seen it written many times now that everything from an Amp clipping to Comb Filtering and other such woes, while audible, you also have to know what to listen for. Consider that Poes, Shady, and now Dennis and Gene have all said something similar and how that lines up with Harmon training their test panels.
In some way, there is a certain amount of “ignorance is bliss,” which comes into play. After all, if you don’t know what Comb Filtering sounds like then what does it matter? How many people are the same with poorly designed subwoofers [read; one note wonder or fartbox], until they hear a proper one in use?
While I agree that having 3 horizontal MTMs across a narrow front is absolutely not ideal, the level of audibility of the academic problem is in the ear of the beholder.