Yeah, okay, this makes sense. I may not like it, but it makes sense. Out of frustration, and telling myself I'd dragged my feet long enough, I bounced a melody track to audio so I could access the Sonitus EQ. And all I gotta say is, what took me so long? Geez, what a difference. I was finally able to filter a couple of annoying characteristics out of an otherwise nice sounding instrument. So I guess this is what I'll do from now on.
Now, I have known for quite some time that if I have only a single instrument associated with a soft synth, then I can use FX for the soft synth to get the sounds I wanted for that single instrument, but the stumbling block for me had been what to do with a single instrument when several were being handled by a single soft synth. Well, now I know.