Ah, you're right in that it's cool and something interesting to do and learn so thanks for that.
There are also many different ways in sonar to "skin the cat." For individual kit pieces that I want to work with in audio, like a kick or a snare or whatever. If I have it in AD2, you can mute everything but what you want. So separate your midi into different tracks, mute everything but the piece you want, then freeze the synth.
That creates an audio track with the selected kit piece in it, bounce that track to a new track, unfreeze the synth.
Now you have an audio track of the kit piece like you wanted by replacing it in DR.
You also still have the synth, the midi tracks, and lots of choices available. Just another way to do the same thing.
Like you, I do like to understand all these choices. I feel like I have attained a masters degree in sonar the past few years. Most of it learned from this forum, so all good!!
gabo