Well film presentation is either important to you or it isn't. If it is then it should be apparent what formats are supposed to be larger and why ARs are expressed with height as the constant 1).Scope bigger than everything else never made sense to me.
The panels in these projectors are 16:9, or more accurately in the NX line they are 17:9.
If you are using a scope screen, then you are not using the full panel of the projector. You are using a smaller piece of the panel. You are not using the all the pixels or all the light. It only makes sense to me that 16:9 or 17:9 would be bigger than scope, as you are actually using more of the projector's panel and accessing more of its light.
Of course if you use an anamorphic lens that's a whole different story. But an anamorphic lens is not something that these projectors come with by default. They are an extra addon.
So you feel black pixels in the screen border vs black pixels outside the border is better. Why exactly? You're not activating any more of the panel showing a scope film on a 16:9 screen. In fact it's likely you're using native and using less pixels than a person using zoom on a wider AR screen. Front projection frees you from the limitation of flat panels and a fixed AR.
An anamorphic lens is simply a different approach to the same solution with added costs and benefit.