I have been experimenting with a three-master design and I have done maybe 5-6 rounds for each master. In theory I suppose if you like your results you can just do one round. But speaking partly from the point of view of an idealist and partly from the point of view of practicality, and assuming you don't enter silly values and have fairly good spacing to start - how many rounds of adjustment is Kern On designed to require?
I noticed too that at first Kern On wants to know about letters and later numbers and punctuation which suggests a pattern at work. So I wonder as a rule of thumb are you nearly done if you are being asked about small numbers or something like that?
I am also guessing that a complete Kern On process might be something like 4-6 hours per master. Does that sound right?