As long as they think they've enough memory to load 'em!
Tip: drop the .sf2 file into the STS's pool first as an .sf2 file can often contain > 1 instrument (or patch...) You can then load the individual patches from the pool into STS.
How about the old (up to 2.04 afaik) Sample Players? There was 2 versions, one with filter and one without. No individual outputs, but light on dsp and loads .sf2 if I remember well.