Hi Micha -
They are. When you save a new named view that has a specific clipping plane active, that clipping plane will be included in the “definition” of that named view. I always create my named views by starting with an unclipped scene and call that “v0”. When I add a clipping plane, I create a new named view “v1” (or, for architectural scenes, “p1” or “x1” depending on whether it’s a plan view or section view). When I need a particular view, I just type “v0” or “v1”, “p2”, etc on the command line and the view is restored with the correct clipping plane active.
It was experimented with quite a bit earlier in the Rhino 8 WIP cycle but that didn’t turn out well enough to be included. It’s possible that this is looked at again at some point in the future.
-wim