Since noone else has answered, I'll give it a try. I've never been involved in a live setup, so take my suggestions with that in mind. Besides, I don't have the Steinway B, so I'm not very familiar with that sound (except from recordings I've heard with that instrument used).
There aren't any presets specially for a piano sitting in a mix. Maybe the presets with the word Recording in them, can be good starting points. That goes for all the pianos, and you can always copy all parameters from any preset of any other instrument (except the model of course) and copy them into a preset for the Steinway B.
There is one preset for the free (legacy) model C3, called C3 Mix Recording. You could copy that into the Steinway B, as well. It seems that preset just raises the mids and highs, to get a bit more of a cutting sound. What concerns microphone positions, the Recording presets very often have two close mics, and two out in the room.
What you just need to do, is experiment, until you find what could work in your situation. Assuming you're not going to practice with the band before hand, you can try mixing a piano recording with other instruments in a DAW, but time for that may be running out?