Just a small idea, but perhaps add an on click gui that lets you set output priorities on lanes? Like a lane swapper, or push everything to one side or the other, or only let a certain item on one lane.
This was already on my TODO list, but I will increase its priority as a result of this post. Thanks for the feedback! It is much appreciated.
The next build should add support for bob's and improve the balancer graphics (make them properly draw over belts so that they can go back to being the correct size). But the release after that would be a perfect time to add some kind of filtering capability.