There's a few problems. Venues are often used to dealing in mono because the majority of the acts will operate that way (guitars etc) rather than in stereo.

It shouldn't really be an issue tbh, and any decent sound engineer/venue should be able to accommodate stereo signals, but it isn't always the case - especially in smaller places. As a result, it can wind up safer to just make sure you have a mono output to the desk so you don't lose out on the notes that are panned to one side or the other.

There's also the train of thought that the stereo panning doesn't really work well in the live environment anyway, since people will be stood all over the place - so won't get the benefit of the effect. It can end up with them getting an unbalanced experience of the track if they are stood nearer one speaker stack or the other.

I'm curious, why is mono preferred when playing live? What problems does stereo introduce?

To be safe, I've got mono versions of all my tracks now for playing live. At least then if the mixer dies or something it isn't a big hassle to just fire into another one. It's helpful if you want to add mono fx pedals at the end of the chain as well.

you can also pan the entire channel (each individually) for your songs on the fly via the song screen by simply pressing b + left or right over the specified channel. saved my ass in the past running through a janky set up

yeah, that's never fun.. much easier to do it with a hardware mixer if you can spare the channels

Awesome. Seems simple enough. I was really dreading going in and changing all those commands.

yeah, each stereo channel also works in mono if you only plug one cable in to the L jack.. so with that mixer you could plug one game boy's outputs into channel 1 & channel 2, and a second one with one channel into 3/4's L and the other into 5/6's L..

I basically have that exact mixer. The mono inputs are the first two?

either option could work, though the easiest way would be to just use mono inputs on a mixer and center both channels.. if you're using a normal (non-dj) mixer similar to this, at least

In two weeks I will be playing live for the first time. I have noticed that running stereo can sometimes be a nightmare and a lot of threads in this forum suggest having a mono mix for live shows. My question is simply..

Do I need to make a new .sav with all "O" commands removed as well as all instruments LR?

Do I put all channels on the song screen to LLLL?

Please and thank you.