This may be kind of a confusing answer, but it's my opinion nonetheless

When mixing, I like stereo tracks to be handled as 2 individual MONO tracks. It helps me define the 'width' of the stereo field for the tracks as well as the placement (and volume/EQ of the individual L/R signals).


"how far right-left a stereo piano track goes" is defined by the sample or recorded track(s), unless you separate them to MONO, then you can put L or R anywhere you want .. though you you are still stuck with how much of the L/R is bleeding between the two tracks.

Make your sound your own!
.. I do not work here, but the benefits are still awesome