Interesting.

I'm running my R20 in USB interface / stereo mix mode and the faders do work. I didn't think about trying to apply any effects. I'll play with that, for fun, but I'd definitely add them in the DAW as well. (I really only use my R20 for multitrack recording and do all my effects in the DAW. I like it, and it can do a ton standalone, but my workflow really just needed a multitrack recorder and I could have probably spent a lot less. It just looked like fun...)