Hi Harpo
I was one who gave one of the (hopefully) interesting replies to your first post (
Session Drummer 3 -vs- BFD?? 
) and I can assure you my answer was correct.
This is what I do and it works for me, there may of course be other, and even better ways so perhaps others here will give you some.
Firstly, when when loading BFD via the synth rack I will check the option,
"all synth outputs to stereo" which is indeed slightly confusing for it is a lie or at best a half truth. What is gives you in reality is, 8 stereo outs and 16 mono outs. When you select this option go to the BFD mixer page, there at the bottom of each individual channel you will see your ouputs, they wlill all say, "Master" as that is their default. BFD doesn't rout them for you, it just gives you the routing options for you to set up how you want.
Click on and of these outputs that say master and you will see your ouput options, the fisrt will say "master" and it's stereo, the next are numbered 2 to 8 these are also stereo and the following. "numbered 1 to 16" are mono.
Really you should just experiment, load up BFD, load a BFD 2 preset, (these give you, both kit and mixer setting in one preset and will often have a midi loop loaded too so you can just hit play once the kit has loaded)
You'll notice that in the sonar track (or console) view the meters will be registering but only on the first 2 channels. This is because (as it says) BFD defaults to the stereo master. Now, whilst bfd is playing a loop, go back to the BFD mixer and select a different output (remember, the bottom of the channel where it says master) you should now see whatever outputs you selected BFD's mixer will now be registering on sonars meter.
I also posted a link for you on your other thread
(
http://www.youtube.com/watch?v=r0oEN3P73pk&feature=related))
It's a hard tutorial to follow because he covers so much and too quickly for those who are noobs as was I when I first watched it, but it's actually a really good tutorial for anyone mixing drums.
Next question? :)
Good luck, you will fall more in love with BFD and feel (hopefully) better for the knowledge acquired.
Steve