An idea crashed into my head over the weekend and now I'm committed to seeing it through.
In addition to the Spritz cipher as a DRBG for PassGen3, what if I also added the ChaCha8 and Trivium stream ciphers, allowing the user to choose?
ChaCha8 is written and passes test vectors. Implementing it though means adding "absorb(data)" and "squeeze(count)" functions so I have a consistent API with Spritz.
Trivium is written but doesn't pass test vectors. I'm pulling my hair out as to why.