I have researched it, and nothing I see tells me otherwise. That's why I'm saying wait till some reviews are done. Point me at your research and lets see what you mean?
What I mean is don't be making stuff up like that. You are making the claim that the only difference between the 5DS and 5DS R is that the 5DS R does a little in-camera post-processing sharpening. That is absolutely absurd. You've made up that little "fact" out of thin air.
I don't need to prove anything because I am not making a truth claim. You're claiming to know the difference between the models that is at variance with the claims of the manufacturer, so you bear the burden of proof. You show us the documentation that proves your assertion.
The above is your baseline - we are being told by Canon that the 5DS R includes a second filter that cancels out the effect of the low-pass filter. It's on you to prove that false - that there is no actual cancelation filter; that all that is really happening is a little in-camera post-processing sharpening.