Of course, unless the guitar has stereophonic pickups and output jacks, it's simply mono with two speakers. I suppose you could run an effect into one channel and not the other with a splitter box. , or use a stereo effect that, say, bounces delays from one channel to the other. Etc.
I went through a phase where I bi-amped for a while.
It started when for a couple of years I was with an outfit playing concert volume rock&roll, outdoors.
For a while I used an Ampeg V4 & 4X12” cabinet.
Then expanded to an additional 1X12” cabinet so the drummer could hear me.
The 1X12 cabinet had a Celestion Mesa Black Shadow speaker, which could be heard above the 4X12 cab because it cut through better.
This led to an additional Ampeg VT-40 amp, which I set for highs, then let the V4 provide “oomph” and wallop, underneath.
Then I split my guitar signal through a stereo chorus set to minimum, and added a delay to one leg. Sounded huge! Suddenly I understood why a Tom Scholz Rockman w reverb sounded the way it did.
I was accused of using a Dumble because it sounded a bit like Robben Ford (the sound, if not the chops).
Eventually I was using a Mesa Stereo 295 stereo power amp, Quad preamp, and earplugs! I ran the delay through the effects loop and split it. It was essentially bi-amping with delay on one bounce with no initial pulse on one side.
Not stereo really, just thickened bi-amping, but sounded great and the speaker array wasn’t all that sensitive to placement.