Let me tell you this is a story.
I reread and Zang uses the bulb release...
So, Maxim 6 does not work with the USB cable, but it was sorta working in 5, but not for long sequences of images. I have complained again.
I heard SequenceGenerator Pro works with USB (no it does not).
WHWang uses some opensource software that obviously works for him with USB but I recall it did not integrate with other software, for mount control.
BackYard NIKON worked in its Beta form with USB, have not checked to see where that is.
NIKON has their own proprietary SDK and APIs etc etc and I think you have to register with them as a developer to get access. They have their own expensive remote control software... hence I think they poison the pot a bit. Really worked for SONY, right.
I do not know what BPP is... next chapter in this mystery.
PS I have so much light pollution the images I have gotten in the Bay Area are pretty much washed out... but maybe with good flats and darks.