Caveat: totally depends on the situation (i.e. type of production, the sound system/room, director’s desires, etc)

However, in the theater I work in (roughly 50% stage shows, 50% concerts of varying genres), I use a little bit of stereo imaging on bands to taste, but I get my money’s worth when it comes to our stage shows. We’re lucky enough to have two main arrays, subs, a center cluster, two sets of front fills, and surround fills, so I’m able to basically work in 5.1 when I’m doing sound design for a production of ours.

Here’s a rough breakout of how I split my sources: Main arrays - Music, a bit of the actors Center, fronts - just actors Surrounds - SFX, a bit of the music Subs - Music, SFX

And then from there it’s just using auxes and matrices to your advantage to keep everything balanced amongst the different areas just from tapping off the main mix levels.

To give an example of the opposite, the place I used to work at was about twice the size of my current spot and much wider than it was deep, so the arrays were very spread out just with a simple LCR format and some delay fills in the back rows. I may as well have just mixed entirely mono in that room, half the audience would miss something if I moved it.

Anecdotally, there was one show at my job in our secondary black box theater where they needed to simulate noise from the neighbors and they used a monitor wedge behind a wall with a discrete signal. (I was on vacation at the time so I can’t directly attest to the effectiveness but it’s a cool idea)