Agree with the above. Good optics for shooting are good enough for much target finding, shot fall spotting, but not the eyebox. Mounting other than on a rifle is a PITA.
One of my favorite things is to shoot with a friend, and we're both behind the rifle. Started at a class, so we got more shooting time in, but ended up being a pretty good way to spot in some cases, and for tricky stuff the spotter can load, and there's an immediate followup available also, but usually it's one at a time shooting, the spotter is empty.
Also can be easier to spot trace since you are right next to the shooter, esp places where getting a spotter behind/above the shooter is hard (or dangerous).
I upgraded my spotter to an LMSS2, and it's made me very happy, plus plenty popular so accessories are available to make them better, even, such as
derek1ee.