One important aspect (...not an intended pun...) is that using a Paint Mix that has a decided Grey tint to attenuate Black Bars, yet does not proportionately compromise White and Colors is what allows the "near black" of Format Bars to recede virtually to unnoticeable levels.
related, Anamorphic modes are intended for use with Anamorphic Lenses, who themselves correct the "Stretch". However one MUST be using such a expensive outboard A-Lens, and those individuals are in the extremely small minority...at least in comparison to the majority of PJ/Screen owners. Of course on AVS, if you chose the right Forum, there seems to be a veritable plethora of such users.
Ever since late 2012 when the PanasonicPT-AE8000u made the adjustments for optimizing the size of 2.35:1 / 16:9 a nearly a fully automatic process, and JVC followed suit closely thereafter, the "Poor Mans Scope Solution" has gained popularity. I myself immediately embraced the idea of using a border-less , as the vast majority of my posted Theater / Screen builds clearly indicate.
And I speak with the authority granted me by actual experience that in the ensuing years, and having listened to literally 10s of thousands of "live" comments, that virtually no one ever stated that it wasn't wholly desirable and cool. And that included 1080p content enlarged out to 144"-180" diagonal sized 2.35:1 . E-Shifted content and Native 4K is just gravy on the 2.40:1 potatoes.
Somewhat sadly, I feel that JVC is sorta lettin' down the Native 4K'ers by not making the sensing of Format changes fully Automatic. The same for Epson. But at least they do have the option.