Only thing I can help with is this- Hunt in disc and if targets are scarce due to it being hit hard or due to bad minerals, flip to pin point mode, full volume, full sensitivity, and watch how suddenly the beach comes to life. When I first saw what PP could do it made a dead badly mineralized beach like virgin ground. Over a hour or two in disc with few targets in my pouch, and then when I flipped to PP I filled my apron with a large amount of clads in no time. I'm even going to use PP at some of my less trashy/deep target land sites where the potential of old coins at PI-like depths out of the reach of VLF machines will still be in reach of the PI-like ability of PP mode.
I didn't even need to turn sensitivity all the way up on that beach and instead kept it where it was stable for disc, but they say (and I've seen) that you can go full blast with sensitivity in PP mode even in the worst of grounds with no issues. Also, I kept volume all the way down, yet my tests confirm that full volume does give PP mode even more depth like I had heard in the past.
If targets are plentiful in disc, which they usually are due to the ultra deep mineralized penetrating power of BBS, then I stick with disc on the beach, but if they are scarce, or I want to concentrate on the ultra deep signals and ignore the "fluff" shallower light stuff (which usually ain't gold rings), then I'll use PP and only go after those deep soft whispers to get down to the heavier stuff where gold rings and silver coins should be sitting. But then again a fresh dropped ring could be shallow.