Here’s a blog post that I found while looking into this issue, it explains it from a modeler’s view:
The money quote:
So what I want to see is a transparent disc of the correct propeller colour(s), with the colour density at each radius matching the relative amount of prop blade and empty space at that radius.
(Not sure if that’s possible with the tech we have, but can the disc have realistic reflections?)
There’s another argument for “transparent disc” style prop animations: even when you turn off reprojection, even if you’re flying on a flat display, the Asobo graphics engine seems to produce a distortion effect. Go flying in VR on a cloudy day at dawn or dusk, and try setting the prop rpm so the prop animation rotates slowly (e.g. in the JustFlight Arrow: 2400-2500 rpm). The distortions are most visible wherever there’s contrast. This is what triggered me to look into this issue: I had turbulent cloud layers ahead of me which were bathed in red sunlight, and the whole cloud mass was wobbling and writhing. (At the time, I didn’t realize that a different rpm setting would’ve mititgated the effect.)