Fred, it is not a good idea to think about the S1 as a "preset-machine". You will need to change those (very few) parameters for each and every scenario, even if you use the same instrument. But it's really easy.
Actually, you mostly need to adjust the two values for "Width" (where 1 is the original stereo width of our recordings, 0 is mono) and "Rotation", which allows you to adjust the L/R-positioning of a signal.
As the perceived "broadness" of an instrument or an ensemble gets smaller and smaller as you move away from it, it is not uncommon to collapse a string-ensemble to 60-70% of its original width. Solo-instruments can get as narrow as 23-30%, when we talk about a common orchestral setting with a huge stage and a virtual listening-position about 10 rows back in the audience. The positioning is completely up to you, of course.
HTH,
/Dietz - Vienna Symphonic Library