highlight warnings - on back and in C1

When one is shooting high contrast landscape scenes, I presume we should shoot so there are no blinking highlight warnings (grey or black, or just black?), which even with ND filters is difficult sometimes, so should one aim to underexpose, process without any highlight and shadow warnings in C1, and then selectively brighten/darken areas in Photoshop?

Should one have no highlight/shadow warnings at all in shooting/processing a file?

surely to reproduce a high contrast scene faithfully the finished file would have some extremes or it would look too flat?

Mike