OP here.
My experiments over the past year suggest that there isn’t a Rhino display mode which can be set to reliably display all three of the following: clipped fills, contours on curving surfaces, and line weights set for clipped objects. If there is, I haven’t found it. The best I can get is a different two of those three on any one of the range of view modes Rhino provides.
“Hidden”, a display mode available with Visualarq (a parametric architectural plug-in I regularly use) is the only mode I feel I can rely on to do those three things at once. (I think I can get it to show intersecting planes reliably, but that’s another source of difficulty I’m not sure I’ve mastered.)
[But Hidden’s only useful for lines. Hidden doesn’t shade, render or texture. I believe Rhino has problems displaying lines with shading in a view because Rhino constructs and displays objects made of planar facets on which to display shading, and these display objects too often severely occlude the linework in most views for the combination to be reliable.
So I double up every detail view, using a Hidden mode view for linework on one layer, on top of a rendered mode view for shading, shadows, and rendered textures. I have separate layers for these two detail views on my project template and use “copy objects to layer” to create the Hidden one once I have the Rendered one the way I like it.
It’s the only solution I’ve found that works. It’s a bit laborious and pitfall-prone but I’ve streamlined it.
(Locking the views is especially crucial to avoid headaches with this two-view setup, but heed this: There’s a bug in the current Rhino. Though group-selected views will be locked after ‘lock’ is checked for them in the properties panel, the check won’t display for them when properties is next open - though they will in fact be locked. Management can get confused.)
(Also - A locked detail view can’t be brought to front or sent to back, they have to be unlocked for that. Don’t forget to lock them again. Separately if you want properties to reliably tell you whether or not they are. Pitfalls.)]