I shoot from one of those Outers swivel gadgets, and look for PD's with my riflescope. It's a Zeiss, and after all day my eyes aren't tired.
This does not work so good with lesser scopes. My partner uses binocs.
I think a spotter would just take up sp0ace as far as I am concerned.
Now, if you had a good one with a camera mount, I can see an opportunity for some neat shots.
HM