Project complete! Had some major anxiety when I discovered a fissure/crack in the Silestone that radiated perpendicular from one of my my intended cuts. Almost abandoned the entire project. Fissure wasn't large (that's why it went previously undetected) so I went for it. Trying to cram my 6' 4" body under the cabinets was a challenge. Our attempts at containing the slurry offspray was about 90% effective. Really- on the ceiling?
Made a small overcut but it will be concealed by the lip of the rangetop. I purchased a slide-in with an overhang so I had some room for error in my cuts. I needed it.
I used a 5.5 amp Ryobi grinder with an Avanti Diamond Turbo blade. Lots of water provided by a hose and my wife's steady hand. If the cuts were to have been visible, my setup was not sufficient. Nor my skill. 45 minutes for setup, 20 minutes for cutting, 30 minutes for clean up. I would do it again. When the range is installed on Thursday, I will post some photos.
Oh, no effect on the crack. Same as before....whew!