The splitter applies -6dB to each half, which then sums back to unity when both are mixed together. Sometimes though, you want to pass the dry signal and mix in a small amount of fx. Parallel distortion/comp/etc. That kind of thing.
Currently the max is +3dB for both channels, so you need to add a gainer to put one channel at unity. Making +6dB the max would fix that. Minor change, but would be nice.