Indeed, manual focus with focus peaking might be a practical way to use the D850 hand held with silent shutter. So far I've mostly used the AF, and noticed that in low light the larger focus area can focus more securely but sometimes on the wrong target (within the selected area however); in some situations wide area AF focused on a brightly lit and detailed background instead of dimly lit subject in the foreground, whereas the pinpoint AF is very precise but might be difficult to use hand held because of camera shake and subject movement. I think I will start practising the use of manual focus for this kind of shots where I need to use LV hand held, such as when shooting from above crowd's heads. Silent shutter is then an additional option once the focusing technique is mastered. Still, I am used to the real-time image of the OVF and it is difficult to time shots using the LCD LV. Not having lag-free shooting, this leads to the use of high fps to catch moments which then fills up memory cards and hard drives unnecessarily. I think the OVF shooting experience is much better for photographing people; AF works without hunting, there is less lag, the subject is seen as a large part of the visual field when using the viewfinder and generally it is a more enjoyable experience than using LV, but for some situations, LV is necessary. For static subjects with the camera on tripod, LV is great, of course.
The sound from high fps within LV is less loud than when using the OVF, even when using the mechanical shutter (which is what I normally use as my subjects are moving and the lights are often flickering).