Thanks for both your detailed response and your helpful tips both at the main thread and how to look for a specific guy’s posts.
RNPs: Hmmph 
I was used to using those before but, if the plane can’t do it for real, and that’s now modeled, then I guess I’ll have to live with it. It is disappointing to learn this, however. Still, it’s only a minor inconvenience NOW THAT I KNOW RNP glideslopes won’t capture, whereas before I was expecting that to happen :).
ILS GS Not Capturing: I consult the Navigraph approach plates in Navigraph Charts itself running outside the game, rather than the in-game toolbar pop-up because there’s less lag with that way. I’ve never see an “AUTHORIZATION REQUIRED” note. And I’m always hitting GS from below at the published FAF altitude. HOWEVER, as I’m flying my TBM in FSE, that meant flying in Saudi down by the Yemen border, then across to Kenya, Uganda, and on to Tanzania. So perhaps the nav data isn’t so good in that part of the world. But at least I wasn’t shot at.