Very cool project. Obviously this is not meant to be a commercial product, but it kinda highlights why these things generally aren't. It's just a lot of things that don't really make that much of a difference over just having two regular old pickups.
I think the more interesting usecase here is running the signals to different amplifiers or plugins. I find that 8-strings especially put a lot more demand on the amplifier itself. If it can't handle the low end, the lowest string ends up sounding like "flumph" instead of "chunk".
Then you get into issues like you'd maybe want less bass on your low strings but then your high strings sound thin. I've successfully used Fractal's pitch follower to control modifiers to alter the amp settings based on which notes are played. It doesn't unfortunately track the 8th and 7th string pitch properly (seems to be designed for 6-strings) but works well enough to tighten the lows and sweeten the highs.
With separate outputs for strings, you could solve this by just running through different signal chains.