Though I don’t understand what you want to do exactly by BCR2000, maybe you don’t know well about what Duplex can do.
For example, have you already tried “Mixer parameters” option in the Effect app?? (see the image)
If you show the needed sliders in the effect box in the Renoise mixer, they will be mapped to the BCR’s knobs automatically. It’s a bit tricky solution though, it may be a useful workaround.
2505 
Also I tried to explain “how to start editing duplex files” before. Anyone can make a custom map (to some degree, though).
I agree that it’s not very easy for a non-programmer (actually I’m also a non-programmer 
), but I think it’s worth a try.
But on the other hand, It seems that the default control-map for BCR2000 has become slightly old now.
In the case of the workaround above, we need to map the Track Selector somewhere, for example.
Maybe we need more suitable custom BCR map for the current Duplex 0.98.
Shall I try to make it if needed ?? 