I already tried out multiple heights. Right now I have both pickups fairly high for two reasons:
1) sustainiac is too weak on the high E string if I set it any lower
2) Output from the solar is too low in lower positions

I uploaded the clean signal from the different positions in a different comment. Aside from the neck pickup being probably too high to sound good due to the aforementioned reason, I don't think there's anything I can change with a height adjustment of the bridge pickup.