Given the history of movies and lens formats achieving true OAR in all cases is going to be dicey if not impossible. Current and past theatrical presentations have a history of incorrect aspect ratio, as do DVDs, LDs, VHS, broadcast TV, etc.
Add to that situation the vagarities of the presentation medium (movie screen, CRT, fixed pixel, whatever) and OAR becomes even more fleeting.
Arguing about a fraction of a percent OAR on present-day consumer displays is arguing for argument's sake. We could argue about the cropping imposed by the width of subpixel barriers which are present throughout the *entire picture* but it wouldn't matter -- there is no content on the video medium that could be displayed to that resolution.
Despite the huge amounts of money some people have poured into a home theater, no consumer home video product is capable of reproducing the movie *exactly*. Given the inaccuracies of the medium, display, mastering, etc., when is "too much" concerning screen fill, either way, within the limits of artist and consumer acceptance? Movies and videos are shot with a "safe area" in plain view of the cinematographer because the *cinematographer* knows that absolute perfection isn't going to occur at the final end product.
So-called "true" OAR is only going to be found with a carefully controlled theatrical presentation with a carefully restored and printed print with absolutely perfect projection lenses that perfectly complement the shooting lenses. These perfect projection lenses must then perfectly match the viewing screen. Anything else is a lie.
Until these exacting laboratory standards can be perfectly reproduced in a home video environment a compromise is necessary if one wishes to participle in reproduced entertainment on a consumer level. The holy grail for *reproduced* entertainment is perfect reproduction. Hasn't happened yet. There is no substitute for the original performance.
Oh my. My entire music and movie collection, and possibly every movie I've ever seen in a theater is wrong. C'est la vie.
The quest for perfection is noble. If that's the quest, enjoy. It will no doubt be rewarding with plenty of surprises. We look forward to the day when the tireless efforts of certain AVS members have provided us with broadcast OAR perfection. Indeed, there are several movie archivists that through their hurculean efforts have rescued films from the brink of oblivion. It's amazing that that certain movies still exist in whatever format. The problem for many people is that the single-minded pursuit isn't practical. As a society we're lucky that people pick and carefully choose their pefections. It's strange, but these same, wonderful movie archivists may just be content with a bowl of Campbell's soup. Thankfully, many/most people accept imperfections and each person's level of acceptance of those imperfections.
Life goes on.