JOBO C-41 1L Kit, how many 120 rolls can it process within a timeframe?

[moodlover]

I'm using the basic Paterson tank that says 500ml on its bottom and the JOBO C-41 1L kit with 120 film. I am a bit confused as to how many 120 rolls it can safely process with good results and within what time frame. Some people say processing within 2 weeks is ideal and some say 2 days (which one is it?). I'm also wondering if I can process 8 rolls or 4, since the instructions I believe say 4:

I processed 8 with this kit so far and have been quite dissatisfied with the scans of the last 4 (which I'm trying to figure out if thats a developing issue or digital issue).