Mario, you should be able to have as many midi tracks as you want now.
You could have one instance of the BB plugin on one track, this will send all the midi tracks/ channels to other tracks in the DAW with different Virtual Instruments on them,
now on another track you could have another instance of the BB plugin with more midi tracks sending to more tracks with virtual instruments.
Now you could have another instance that generated up 7 (or more) of the same midi track or different ones (I think they are going to add MultiRiffs for Midi also) and add a re-channel midi fx so all the channels will get sent to the one virtual instrument, then you just solo each track one at a time til you find the one that fits best.